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Sample records for brain imaging agents

  1. Potential new approaches for the development of brain imaging agents for single-photon applications

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, F.F. Jr.; Srivastava, P.C.

    1984-01-01

    This paper describes new strategies for the brain-specific delivery of radionuclides that can be used to evaluate regional cerebral perfusion by single photon imaging techniques. A description of several examples of interesting new strategies that have recently been reported is presented. A new approach at this institution for the brain-specific delivery of radioiodinated iodophenylalkyl-substituted dihyronicotinamide systems is described which shows good brain uptake and retention in preliminary studies in rats. Following transport into the brain these agents appear to undergo facile intracerebral oxidation to the quaternized analogues which do not recross the intact blood-brain barrier and so are effectively trapped in the brain. 49 refs., 9 figs., 1 tab.

  2. F-18 Polyethyleneglycol stilbenes as PET imaging agents targeting A{beta} aggregates in the brain

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    Zhang Wei [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Oya, Shunichi [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kung Meiping [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Hou, Catherine [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Maier, Donna L. [Department of Neuroscience, AstraZeneca, Wilmington, DE 19850 (United States); Kung, Hank F. [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States) and Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States)]. E-mail: kunghf@sunmac.spect.upenn.edu

    2005-11-01

    This paper describes a novel series of {sup 18}F-labeled polyethyleneglycol (PEG)-stilbene derivatives as potential {beta}-amyloid (A{beta}) plaque-specific imaging agents for positron emission tomography (PET). In these series of compounds, {sup 18}F is linked to the stilbene through a PEG chain, of which the number of ethoxy groups ranges from 2 to 5. The purpose of adding PEG groups is to lower the lipophilicity and improve bioavailability. The syntheses of the 'cold' compounds and the {sup 18}F-labeled PEG stilbene derivatives are successfully achieved. All of the fluorinated stilbenes displayed high binding affinities in an assay using postmortem AD brain homogenates (K {sub i}=2.9-6.7 nM). Labeling was successfully performed by a substitution of the mesylate group of 10a-d by [{sup 18}F]fluoride giving the target compounds [{sup 18}F]12a-d (EOS, specific activity, 900-1500 Ci/mmol; radiochemical purity >99%). In vivo biodistribution of these novel {sup 18}F ligands in normal mice exhibited excellent brain penetrations and rapid washouts after an intravenous injection (6.6-8.1 and 1.2-2.6% dose/g at 2 and 60 min, respectively). Autoradiography of postmortem AD brain sections of [{sup 18}F]12a-d confirmed the specific binding related to the presence of A{beta} plaques. In addition, in vivo plaque labeling can be clearly demonstrated with these {sup 18}F-labeled agents in transgenic mice (Tg2576), a useful animal model for Alzheimer's disease. In conclusion, the preliminary results strongly suggest these fluorinated PEG stilbene derivatives are suitable candidates as A{beta} plaque imaging agents for studying patients with Alzheimer's disease.

  3. MR-Guided Delivery of Hydrophilic Molecular Imaging Agents Across the Blood-Brain Barrier Through Focused Ultrasound.

    Science.gov (United States)

    Airan, Raag D; Foss, Catherine A; Ellens, Nicholas P K; Wang, Yuchuan; Mease, Ronnie C; Farahani, Keyvan; Pomper, Martin G

    2017-02-01

    A wide variety of hydrophilic imaging and therapeutic agents are unable to gain access to the central nervous system (CNS) due to the blood-brain barrier (BBB). In particular, unless a particular transporter exists that may transport the agent across the BBB, most agents that are larger than 500 Da or that are hydrophilic will be excluded by the BBB. Glutamate carboxypeptidase II (GCPII), also known as the prostate-specific membrane antigen (PSMA) in the periphery, has been implicated in various neuropsychiatric conditions. As all agents that target GCPII are hydrophilic and thereby excluded from the CNS, we used GCPII as a platform for demonstrating our MR-guided focused ultrasound (MRgFUS) technique for delivery of GCPII/PSMA-specific imaging agents to the brain. Female rats underwent MRgFUS-mediated opening of the BBB. After opening of the BBB, either a radio- or fluorescently labeled ureido-based ligand for GCPII/PSMA was administered intravenously. Brain uptake was assessed for 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid ([18F]DCFPyL) and YC-27, two compounds known to bind GCPII/PSMA with high affinity, using positron emission tomography (PET) and near-infrared fluorescence (NIRF) imaging, respectively. Specificity of ligand binding to GCPII/PSMA in the brain was determined with co-administration of a molar excess of ZJ-43, a compound of the same chemical class but different structure from either [18F]DCFPyL or YC-27, which competes for GCPII/PSMA binding. Dynamic PET imaging using [18F]DCFPyL demonstrated that target uptake reached a plateau by ∼1 h after radiotracer administration, with target/background ratios continuing to increase throughout the course of imaging, from a ratio of ∼4:1 at 45 min to ∼7:1 by 80 min. NIRF imaging likewise demonstrated delivery of YC-27 to the brain, with clear visualization of tracer in the brain at 24 h. Tissue uptake of both ligands was greatly diminished by ZJ

  4. Uncertainty analysis for absorbed dose from a brain receptor imaging agent

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    Aydogan, B.; Miller, L.F. [Univ. of Tennessee, Knoxville, TN (United States). Nuclear Engineering Dept.; Sparks, R.B. [Oak Ridge Inst. for Science and Education, TN (United States); Stubbs, J.B. [Radiation Dosimetry Systems of Oak Ridge, Inc., Knoxville, TN (United States)

    1999-01-01

    Absorbed dose estimates are known to contain uncertainties. A recent literature search indicates that prior to this study no rigorous investigation of uncertainty associated with absorbed dose has been undertaken. A method of uncertainty analysis for absorbed dose calculations has been developed and implemented for the brain receptor imaging agent {sup 123}I-IPT. The two major sources of uncertainty considered were the uncertainty associated with the determination of residence time and that associated with the determination of the S values. There are many sources of uncertainty in the determination of the S values, but only the inter-patient organ mass variation was considered in this work. The absorbed dose uncertainties were determined for lung, liver, heart and brain. Ninety-five percent confidence intervals of the organ absorbed dose distributions for each patient and for a seven-patient population group were determined by the ``Latin Hypercube Sampling`` method. For an individual patient, the upper bound of the 95% confidence interval of the absorbed dose was found to be about 2.5 times larger than the estimated mean absorbed dose. For the seven-patient population the upper bound of the 95% confidence interval of the absorbed dose distribution was around 45% more than the estimated population mean. For example, the 95% confidence interval of the population liver dose distribution was found to be between 1.49E+0.7 Gy/MBq and 4.65E+07 Gy/MBq with a mean of 2.52E+07 Gy/MBq. This study concluded that patients in a population receiving {sup 123}I-IPT could receive absorbed doses as much as twice as large as the standard estimated absorbed dose due to these uncertainties.

  5. Enhanced therapeutic agent delivery through magnetic resonance imaging-monitored focused ultrasound blood-brain barrier disruption for brain tumor treatment: an overview of the current preclinical status.

    Science.gov (United States)

    Liu, Hao-Li; Yang, Hung-Wei; Hua, Mu-Yi; Wei, Kuo-Chen

    2012-01-01

    Malignant glioma is a severe primary CNS cancer with a high recurrence and mortality rate. The current strategy of surgical debulking combined with radiation therapy or chemotherapy does not provide good prognosis, tumor progression control, or improved patient survival. The blood-brain barrier (BBB) acts as a major obstacle to chemotherapeutic treatment of brain tumors by severely restricting drug delivery into the brain. Because of their high toxicity, chemotherapeutic drugs cannot be administered at sufficient concentrations by conventional delivery methods to significantly improve long-term survival of patients with brain tumors. Temporal disruption of the BBB by microbubble-enhanced focused ultrasound (FUS) exposure can increase CNS-blood permeability, providing a promising new direction to increase the concentration of therapeutic agents in the brain tumor and improve disease control. Under the guidance and monitoring of MR imaging, a brain drug-delivery platform can be developed to control and monitor therapeutic agent distribution and kinetics. The success of FUS BBB disruption in delivering a variety of therapeutic molecules into brain tumors has recently been demonstrated in an animal model. In this paper the authors review a number of critical studies that have demonstrated successful outcomes, including enhancement of the delivery of traditional clinically used chemotherapeutic agents or application of novel nanocarrier designs for actively transporting drugs or extending drug half-lives to significantly improve treatment efficacy in preclinical animal models.

  6. Amifostine, a radioprotectant agent, protects rat brain tissue lipids against ionizing radiation induced damage: An FTIR microspectroscopic imaging study

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    Cakmak G.; Miller L.; Zorlu, F.; Severcan, F.

    2012-03-03

    Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH{sub 2} groups of lipids decreased significantly and the carbonyl esters, olefinic=CH and CH{sub 3} groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems.

  7. Amifostine, a radioprotectant agent, protects rat brain tissue lipids against ionizing radiation induced damage: an FTIR microspectroscopic imaging study.

    Science.gov (United States)

    Cakmak, Gulgun; Miller, Lisa M; Zorlu, Faruk; Severcan, Feride

    2012-04-15

    Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH(2) groups of lipids decreased significantly and the carbonyl esters, olefinic=CH and CH(3) groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Development of radioactive agent for image diagnosis of brain dopamine receptor

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    Fujita, Motoi; Kitamura, Hideaki; Nakajima, Takashi [Saigata National Hospital, Niigata (Japan)

    2000-02-01

    Recently, MRI is often used to examine pathological degeneration of intracerebellar neurons of patients with Parkinson's disease, Huntington's chorea, spinocerebellar degeneration, etc. However, the efficacy of MRI is still unsatisfactory at present. In this project, the efficacy of SPECT was examined to evaluate the cerebellar functions in the previous year and it was found that the benzodiazepin receptor in CNS was detectable using SPECT with {sup 125}I iomazenil. In this year, ocular movements as one of cerebellar functions was attempted using functional MRI and patients' ocular movements were analyzed on the basis of the saccade during functional MRI imaging by Ober2 (Permobil Sweden). Image of an activated region in the frontal eye field (FEF), supplementary eye field (SEF), parietal eye field (PEF), posterior lobe or cerebellum was obtainable by Ober2-attached functional MRI. Especially, vermis 5, 6 and 7 lobules in the cerebellum were activated and random saccade was much stronger than regular saccade in the cerebellum. These results indicated that functional MRI was usable for clinical evaluation of patients with central nervous degeneration. (M.N.)

  9. Design, synthesis and evaluation of 2-deoxy-2-iodovinyl-branched carbohydrates as potential brain imaging agents

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    Goodman, M.M.; Callahan, A.P.; Knapp, F.F. Jr.

    1986-01-01

    Radioiodinated carbohydrates such as 2-deoxy-2-iodo-D-glucose and 3-deoxy-3-iodo-D-glucose undergo facile chemical or in vivo deiodination which precludes their use as radiotracers of glucose metabolism in tissues. To overcome the problems resulting from in vivo deiodination, we explored the concept of stabilizing radioiodide on a model carbohydrate, (E)-C-3-iodovinyl-D-allose (10) as an iodovinyl moiety. This agent did not exhibit brain specificity but showed low in vivo deiodination which demonstrated for the first time that radioiodide can be stabilized on a carbohydrate. The goal of this study was to develop a deoxy-branched carbohydrate with radioiodide stabilized as a vinyliodide with the objective of achieving high brain uptake. 10 refs., 1 fig., 1 tab.

  10. Brain Delivery of Drug and MRI Contrast Agent: Detection and Quantitative Determination of Brain Deposition of CPT-Glu Using LC-MS/MS and Gd-DTPA Using Magnetic Resonance Imaging

    Science.gov (United States)

    Tabanor, Kayann; Lee, Phil; Kiptoo, Paul; Choi, In-Young; Sherry, Erica B.; Eagle, Cheyenne Sun; Williams, Todd D.; Siahaan, Teruna J.

    2015-01-01

    Successful treatment and diagnosis of neurological diseases depend on reliable delivery of molecules across the blood-brain barrier (BBB), which restricts penetration of pharmaceutical drugs and diagnostic agents into the brain. Thus, developing new non-invasive strategies to improve drug delivery across the BBB is critically needed. This study was aimed at evaluating the activity of HAV6 peptide (Ac-SHAVSS-NH2) in improving brain delivery of camptothecin-glutamate (CPT-Glu) conjugate and gadolinium-diethylenetriaminepentaacetate (Gd-DTPA) contrast agent in Sprague-Dawley rats. Brain delivery of both CPT-Glu and Gd-DTPA was evaluated in an in situ rat brain perfusion model in the presence and absence of HAV6 peptide (1.0 mM). Gd-DTPA (0.6 mmol/kg) was intravenously (i.v.) administered with and without HAV6 peptide (0.019 mmol/kg) in rats. The detection and quantification of CPT-Glu and Gd-DTPA in the brain were carried out by LC-MS/MS and quantitative magnetic resonance imaging (MRI), respectively. Rats perfused with CPT-Glu in combination with HAV6 had significantly higher deposition of drug in the brain compared to CPT-Glu alone. MRI results also showed that administration of Gd-DTPA in the presence of HAV6 peptide led to significant accumulation of Gd-DTPA in various regions of the brain in both the in situ rat brain perfusion and in vivo studies. All observations taken together indicate that HAV6 peptide can disrupt the BBB and enhance delivery of small molecules into the brain. PMID:26705088

  11. Brain Delivery of Drug and MRI Contrast Agent: Detection and Quantitative Determination of Brain Deposition of CPT-Glu Using LC-MS/MS and Gd-DTPA Using Magnetic Resonance Imaging.

    Science.gov (United States)

    Tabanor, Kayann; Lee, Phil; Kiptoo, Paul; Choi, In-Young; Sherry, Erica B; Eagle, Cheyenne Sun; Williams, Todd D; Siahaan, Teruna J

    2016-02-01

    Successful treatment and diagnosis of neurological diseases depend on reliable delivery of molecules across the blood-brain barrier (BBB), which restricts penetration of pharmaceutical drugs and diagnostic agents into the brain. Thus, developing new noninvasive strategies to improve drug delivery across the BBB is critically needed. This study was aimed at evaluating the activity of HAV6 peptide (Ac-SHAVSS-NH2) in improving brain delivery of camptothecin-glutamate (CPT-Glu) conjugate and gadolinium-diethylenetriaminepentaacetate (Gd-DTPA) contrast agent in Sprague-Dawley rats. Brain delivery of both CPT-Glu and Gd-DTPA was evaluated in an in situ rat brain perfusion model in the presence and absence of HAV6 peptide (1.0 mM). Gd-DTPA (0.6 mmol/kg) was intravenously (iv) administered with and without HAV6 peptide (0.019 mmol/kg) in rats. The detection and quantification of CPT-Glu and Gd-DTPA in the brain were carried out by LC-MS/MS and quantitative magnetic resonance imaging (MRI), respectively. Rats perfused with CPT-Glu in combination with HAV6 had significantly higher deposition of drug in the brain compared to CPT-Glu alone. MRI results also showed that administration of Gd-DTPA in the presence of HAV6 peptide led to significant accumulation of Gd-DTPA in various regions of the brain in both the in situ rat brain perfusion and in vivo studies. All observations taken together indicate that HAV6 peptide can disrupt the BBB and enhance delivery of small molecules into the brain.

  12. Brain temperature and pH measured by 1H chemical shift imaging of a thulium agent

    Science.gov (United States)

    Coman, Daniel; Trubel, Hubert K.; Rycyna, Robert E.; Hyder, Fahmeed

    2009-01-01

    Temperature and pH are two of the most important physiological parameters and are believed to be tightly regulated because they are intricately related to energy metabolism in living organisms. Temperature and/or pH data in mammalian brain are scarce, however, mainly due to lack of precise and non-invasive methods. At 11.7T, we demonstrate that a thulium-based macrocyclic complex infused through the blood stream can be used to obtain temperature and pH maps of rat brain in vivo by 1H chemical shift imaging (CSI) of the sensor itself in conjunction with a multi-parametric model that depends on several proton resonances of the sensor. Accuracies of temperature and pH determination with the thulium sensor – which has a predominantly extracellular presence – depend on stable signals during the course of the CSI experiment as well as redundancy for temperature and pH sensitivities contained within the observed signals. The thulium-based method compared well with other methods for temperature (1H magnetic resonance spectroscopy (MRS) of N-acetyl aspartate and water; copper-constantan thermocouple wire) and pH (31P MRS of inorganic phosphate and phosphocreatine) assessment, as established by in vitro and in vivo studies. In vitro studies in phantoms with two compartments of differing pH values observed under different ambient temperature conditions generated precise temperature and pH distribution maps. In vivo studies in α-chloralose anesthetized and renal-ligated rats revealed temperature (33–34 °C) and pH (7.3–7.4) distributions in the cerebral cortex which are in agreement with observations by other methods. These results demonstrate that the thulium sensor can be used to measure temperature and pH distributions in rat brain in vivo simultaneously and accurately with 1H CSI. PMID:19130468

  13. Brain Vascular Imaging Techniques

    Directory of Open Access Journals (Sweden)

    Bàrbara Laviña

    2016-12-01

    Full Text Available Recent major improvements in a number of imaging techniques now allow for the study of the brain in ways that could not be considered previously. Researchers today have well-developed tools to specifically examine the dynamic nature of the blood vessels in the brain during development and adulthood; as well as to observe the vascular responses in disease situations in vivo. This review offers a concise summary and brief historical reference of different imaging techniques and how these tools can be applied to study the brain vasculature and the blood-brain barrier integrity in both healthy and disease states. Moreover, it offers an overview on available transgenic animal models to study vascular biology and a description of useful online brain atlases.

  14. Use of gadolinium-based magnetic resonance imaging contrast agents and awareness of brain gadolinium deposition among pediatric providers in North America

    Energy Technology Data Exchange (ETDEWEB)

    Mithal, Leena B. [Northwestern University, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Patel, Payal S. [University of Arizona College of Medicine, Department of Pediatrics, Phoenix, AZ (United States); Mithal, Divakar [Northwestern University, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatric Neurology, Chicago, IL (United States); Palac, Hannah L. [Northwestern University, Biostatistics, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Chicago, IL (United States); Rozenfeld, Michael N. [University of Arizona College of Medicine, Department of Radiology, Phoenix, AZ (United States)

    2017-05-15

    Numerous recent articles have reported brain gadolinium deposition when using linear but not macrocyclic gadolinium-based contrast agents (GBCAs). To determine the current landscape of gadolinium use among pediatric institutions and the knowledge base of radiologists and referring providers with regard to GBCAs and brain gadolinium deposition. We e-mailed voluntary closed surveys to 5,390 physicians in various pediatric professional societies between January 2016 and March 2016. We used chi-square and Fisher exact tests to compare response distributions among specialties. We found that 80% of surveyed pediatric hospitals use macrocyclic contrast agents. In the last year, 58% switched their agent, most commonly to gadoterate meglumine, with the most common reason being brain gadolinium deposition. Furthermore, surveys indicated that 23% of hospitals are considering switching, and, of these, 83% would switch to gadoterate meglumine; the most common reasons were brain gadolinium deposition and safety. Radiologists were more aware of brain gadolinium deposition than non-radiologist physicians (87% vs. 26%; P<0.0001). Radiologists and referring providers expressed similar levels of concern (95% and 89%). Twelve percent of radiologists and 2% of referring providers reported patients asking about brain gadolinium deposition. Radiologists were significantly more comfortable addressing patient inquiries than referring pediatric physicians (48% vs. 6%; P<0.0001). The number of MRIs requested by referring pediatric physicians correlated with their knowledge of brain gadolinium deposition, contrast agent used by their hospital, and comfort discussing brain gadolinium deposition with patients (P<0.0001). Since the discovery of brain gadolinium deposition, many pediatric hospitals have switched to or plan to switch to a more stable macrocyclic MR contrast agent, most commonly gadoterate meglumine. Despite this, there is need for substantial further education of radiologists and

  15. Brain Image Motion Correction

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Benjaminsen, Claus; Larsen, Rasmus

    2015-01-01

    The application of motion tracking is wide, including: industrial production lines, motion interaction in gaming, computer-aided surgery and motion correction in medical brain imaging. Several devices for motion tracking exist using a variety of different methodologies. In order to use such devices...... offset and tracking noise in medical brain imaging. The data are generated from a phantom mounted on a rotary stage and have been collected using a Siemens High Resolution Research Tomograph for positron emission tomography. During acquisition the phantom was tracked with our latest tracking prototype...

  16. Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf.

    Science.gov (United States)

    Shi, Lingyan; Rodríguez-Contreras, Adrián; Budansky, Yury; Pu, Yang; Nguyen, Thien An; Alfano, Robert R

    2014-06-01

    Two-photon (2P) excitation of the second singlet (S₂) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S₂ state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S₂ state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.

  17. Deep two-photon microscopic imaging through brain tissue using the second singlet state from fluorescent agent chlorophyll α in spinach leaf

    Science.gov (United States)

    Shi, Lingyan; Rodríguez-Contreras, Adrián; Budansky, Yury; Pu, Yang; An Nguyen, Thien; Alfano, Robert R.

    2014-06-01

    Two-photon (2P) excitation of the second singlet (S) state was studied to achieve deep optical microscopic imaging in brain tissue when both the excitation (800 nm) and emission (685 nm) wavelengths lie in the "tissue optical window" (650 to 950 nm). S2 state technique was used to investigate chlorophyll α (Chl α) fluorescence inside a spinach leaf under a thick layer of freshly sliced rat brain tissue in combination with 2P microscopic imaging. Strong emission at the peak wavelength of 685 nm under the 2P S state of Chl α enabled the imaging depth up to 450 μm through rat brain tissue.

  18. Brain hypoxia imaging

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    Song, Ho Chun [Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2007-04-15

    The measurement of pathologically low levels of tissue pO{sub 2} is an important diagnostic goal for determining the prognosis of many clinically important diseases including cardiovascular insufficiency, stroke and cancer. The target tissues nowadays have mostly been tumors or the myocardium, with less attention centered on the brain. Radiolabelled nitroimidazole or derivatives may be useful in identifying the hypoxic cells in cerebrovascular disease or traumatic brain injury, and hypoxic-ischemic encephalopathy. In acute stroke, the target of therapy is the severely hypoxic but salvageable tissue. {sup 18}F-MISO PET and {sup 99m}Tc-EC-metronidazole SPECT in patients with acute ischemic stroke identified hypoxic tissues and ischemic penumbra, and predicted its outcome. A study using {sup 123}I-IAZA in patient with closed head injury detected the hypoxic tissues after head injury. Up till now these radiopharmaceuticals have drawbacks due to its relatively low concentration with hypoxic tissues associated with/without low blood-brain barrier permeability and the necessity to wait a long time to achieve acceptable target to background ratios for imaging in acute ischemic stroke. It is needed to develop new hypoxic marker exhibiting more rapid localization in the hypoxic region in the brain. And then, the hypoxic brain imaging with imidazoles or non-imidazoles may be very useful in detecting the hypoxic tissues, determining therapeutic strategies and developing therapeutic drugs in several neurological disease, especially, in acute ischemic stroke.

  19. Perfusion Imaging with a Freely Diffusible Hyperpolarized Contrast Agent

    OpenAIRE

    Grant, Aaron K.; Vinogradov, Elena; Wang, Xiaoen; Lenkinski, Robert E.; Alsop, David C.

    2011-01-01

    Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized 13C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic 13C images acquired in rat brain with a balanced steady-state free precession (bSSFP) sequence following ...

  20. Brain imaging and autism

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    Zilbovicius, M. [Service Hospitalier Frederic Joliot (CEA/DSV/DRM), INSERM CEA 0205, 91 - Orsay (France)

    2006-07-01

    Autism is a neuro-developmental disorder with a range of clinical presentations, from mild to severe, referred to as autism spectrum disorders (ASD). The most common clinical ASD sign is social interaction impairment, which is associated with verbal and non-verbal communication deficits and stereotyped and obsessive behaviors. Thanks to recent brain imaging studies, scientists are getting a better idea of the neural circuits involved in ASD. Indeed, functional brain imaging, such as positron emission tomography (PET), single positron emission tomograph y (SPECT) and functional MRI (fMRI) have opened a new perspective to study normal and pathological brain functions. Three independent studies have found anatomical and rest functional temporal abnormalities. These anomalies are localized in the superior temporal sulcus bilaterally which are critical for perception of key social stimuli. In addition, functional studies have shown hypo-activation of most areas implicated in social perception (face and voice perception) and social cognition (theory of mind). These data suggest an abnormal functioning of the social brain network. The understanding of such crucial abnormal mechanism may drive the elaboration of new and more adequate social re-educative strategies in autism. (author)

  1. The advantage of high relaxivity contrast agents in brain perfusion

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    Cotton, F. [MRI Center, Centre Hospitalier Lyon Sud, Pierre Benite (France); CREATIS, INSA-502, Villeurbanne (France); Lab. d' Anatomie, UFR Laennec, Lyon (France); Hermier, M. [CREATIS, INSA-502, Villeurbanne (France); MRI Center, Neurologic Hospital, Lyon (France)

    2006-01-10

    Accurate MRI characterization of brain lesions is critical for planning therapeutic strategy, assessing prognosis and monitoring response to therapy. Conventional MRI with gadolinium-based contrast agents is useful for the evaluation of brain lesions, but this approach primarily depicts areas of disruption of the blood-brain barrier (BBB) rather than tissue perfusion. Advanced MR imaging techniques such as dynamic contrast agent-enhanced perfusion MRI provide physiological information that complements the anatomic data available from conventional MRI. We evaluated brain perfusion imaging with gadobenate dimeglumine (Gd-BOPTA, MultiHance; Bracco Imaging, Milan, Italy). The contrast-enhanced perfusion technique was performed on a Philips Intera 1.5-T MR system. The technique used to obtain perfusion images was dynamic susceptibility contrast-enhanced MRI, which is highly sensitive to T2* changes. Combined with PRESTO perfusion imaging, SENSE is applied to double the temporal resolution, thereby improving the signal intensity curve fit and, accordingly, the accuracy of the derived parametric images. MultiHance is the first gadolinium MR contrast agent with significantly higher T1 and T2 relaxivities than conventional MR contrast agents. The higher T1 relaxivity, and therefore better contrast-enhanced T1-weighted imaging, leads to significantly improved detection of BBB breakdown and hence improved brain tumor conspicuity and delineation. The higher T2 relaxivity allows high-quality T2*-weighted perfusion MRI and the derivation of good quality relative cerebral blood volume (rCBV) maps. We determined the value of MultiHance for enhanced T2*-weighted perfusion imaging of histologically proven (by surgery or stereotaxic biopsy) intraaxial brain tumors (n=80), multiple sclerosis lesions (n=10), abscesses (n=4), neurolupus (n=15) and stroke (n=16). All the procedures carried out were safe and no adverse events occurred. The acquired perfusion images were of good quality in

  2. A preclinical murine model for the early detection of radiation-induced brain injury using magnetic resonance imaging and behavioral tests for learning and memory: with applications for the evaluation of possible stem cell imaging agents and therapies.

    Science.gov (United States)

    Ngen, Ethel J; Wang, Lee; Gandhi, Nishant; Kato, Yoshinori; Armour, Michael; Zhu, Wenlian; Wong, John; Gabrielson, Kathleen L; Artemov, Dmitri

    2016-06-01

    Stem cell therapies are being developed for radiotherapy-induced brain injuries (RIBI). Magnetic resonance imaging (MRI) offers advantages for imaging transplanted stem cells. However, most MRI cell-tracking techniques employ superparamagnetic iron oxide particles (SPIOs), which are difficult to distinguish from hemorrhage. In current preclinical RIBI models, hemorrhage occurs concurrently with other injury markers. This makes the evaluation of the recruitment of transplanted SPIO-labeled stem cells to injury sites difficult. Here, we developed a RIBI model, with early injury markers reflective of hippocampal dysfunction, which can be detected noninvasively with MRI and behavioral tests. Lesions were generated by sub-hemispheric irradiation of mouse hippocampi with single X-ray beams of 80 Gy. Lesion formation was monitored with anatomical and contrast-enhanced MRI and changes in memory and learning were assessed with fear-conditioning tests. Early injury markers were detected 2 weeks after irradiation. These included an increase in the permeability of the blood-brain barrier, demonstrated by a 92 ± 20 % contrast enhancement of the irradiated versus the non-irradiated brain hemispheres, within 15 min of the administration of an MRI contrast agent. A change in short-term memory was also detected, as demonstrated by a 40.88 ± 5.03 % decrease in the freezing time measured during the short-term memory context test at this time point, compared to that before irradiation. SPIO-labeled stem cells transplanted contralateral to the lesion migrated toward the lesion at this time point. No hemorrhage was detected up to 10 weeks after irradiation. This model can be used to evaluate SPIO-based stem cell-tracking agents, short-term.

  3. Fluorescence imaging agents in cancerology.

    Science.gov (United States)

    Paganin-Gioanni, Aurélie; Bellard, Elisabeth; Paquereau, Laurent; Ecochard, Vincent; Golzio, Muriel; Teissié, Justin

    2010-09-01

    One of the major challenges in cancer therapy is to improve early detection and prevention using novel targeted cancer diagnostics. Detection requests specific recognition. Tumor markers have to be ideally present on the surface of cancer cells. Their targeting with ligands coupled to imaging agents make them visible/detectable. Fluorescence imaging is a newly emerging technology which is becoming a complementary medical method for cancer diagnosis. It allows detection with a high spatio-temporal resolution of tumor markers in small animals and in clinical studies. In this review, we focus on the recent outcome of basic studies in the design of new approaches (probes and devices) used to detect tumor cells by fluorescence imaging.

  4. Brain tumor (image)

    Science.gov (United States)

    Brain tumors are classified depending on the exact site of the tumor, the type of tissue involved, benign ... tendencies of the tumor, and other factors. Primary brain tumors can arise from the brain cells, the meninges ( ...

  5. Signal Increase on Unenhanced T1-Weighted Images in the Rat Brain After Repeated, Extended Doses of Gadolinium-Based Contrast Agents

    Science.gov (United States)

    Jost, Gregor; Lenhard, Diana Constanze; Sieber, Martin Andrew; Lohrke, Jessica; Frenzel, Thomas; Pietsch, Hubertus

    2016-01-01

    Objectives In this prospective preclinical study, we evaluated T1-weighted signal intensity in the deep cerebellar nuclei (CN) and globus pallidus (GP) up to 24 days after repeated administration of linear and macrocyclic gadolinium-based contrast agents (GBCAs) using homologous imaging and evaluation methods as in the recently published retrospective clinical studies. In a second part of the study, cerebrospinal fluid (CSF) spaces were evaluated for contrast enhancement by fluid-attenuated magnetic resonance imaging (MRI). Materials and Methods Sixty adult male Wistar-Han rats were randomly divided into a control and 5 GBCA groups (n = 10 per group). The administered GBCAs were gadodiamide, gadopentetate dimeglumine, and gadobenate dimeglumine (linear GBCAs) as well as gadobutrol and gadoterate meglumine (macrocyclic GBCAs) and saline (control). Over a period of 2 weeks, the animals received 10 intravenous injections at a dose of 2.5 mmol Gd/kg body weight, each on 5 consecutive days per week. Before GBCA administration, as well as 3 and 24 days after the last injection, a whole-brain MRI was performed using a standard T1-weighted 3-dimensional turbo spin echo sequence on a clinical 1.5 T scanner. The ratios of signal intensities in deep CN to pons (CN/Po) and GP to thalamus (GP/Th) were determined. For the evaluation of the CSF spaces, 18 additional rats were randomly divided into 6 groups (n = 3 per group) that received the same GBCAs as in the first part of the study. After MR cisternography for anatomical reference, a fluid-attenuated inversion recovery sequence was performed before and 1 minute after intravenous injection of a dose of 1 mmol Gd/kg body weight GBCA or saline. Results A significantly increased signal intensity ratio of CN/Po was observed 3 and 24 days after the last injection of gadodiamide and gadobenate dimeglumine. No significant changes were observed between the 2 time points. Gadopentetate dimeglumine injection led to a moderately elevated

  6. Perfusion imaging with a freely diffusible hyperpolarized contrast agent.

    Science.gov (United States)

    Grant, Aaron K; Vinogradov, Elena; Wang, Xiaoen; Lenkinski, Robert E; Alsop, David C

    2011-09-01

    Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized (13)C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic (13)C images acquired in rat brain with a balanced steady-state free precession sequence following administration of hyperpolarized 2-methylpropan-2-ol show that this agent can be imaged with 2-4 s temporal resolution, 2 mm slice thickness, and 700 μm in-plane resolution while retaining adequate signal-to-noise ratio. (13)C relaxation measurements on 2-methylpropan-2-ol in blood at 9.4 T yield T(1) = 46 ± 4s and T(2) = 0.55 ± 0.03 s. In the rat brain at 4.7 T, analysis of the temporal dynamics of the balanced steady-state free precession image intensity in tissue and venous blood indicate that 2-methylpropan-2-ol has a T(2) of roughly 2-4s and a T(1) of 43 ± 24 s. In addition, the images indicate that 2-methylpropan-2-ol is freely diffusible in brain and hence has a long residence time in tissue; this in turn makes it possible to image the agent continuously for tens of seconds. These characteristics show that 2-methylpropan-2-ol is a promising agent for robust and quantitative perfusion imaging in the brain and body. Copyright © 2011 Wiley-Liss, Inc.

  7. SPECT Imaging Agents for Detecting Cerebral β-Amyloid Plaques

    Directory of Open Access Journals (Sweden)

    Masahiro Ono

    2011-01-01

    Full Text Available The development of radiotracers for use in vivo to image β-amyloid (Aβ plaques in cases of Alzheimer's disease (AD is an important, active area of research. The presence of Aβ aggregates in the brain is generally accepted as a hallmark of AD. Since the only definitive diagnosis of AD is by postmortem staining of affected brain tissue, the development of techniques which enable one to image Aβ plaques in vivo has been strongly desired. Furthermore, the quantitative evaluation of Aβ plaques in the brain could facilitate evaluation of the efficacy of antiamyloid therapies currently under development. This paper reviews the current situation in the development of agents for SPECT-based imaging of Aβ plaques in Alzheimer's brains.

  8. [{sup 11}C]SMe-ADAM, an imaging agent for the brain serotonin transporter: synthesis, pharmacological characterization and microPET studies in rats

    Energy Technology Data Exchange (ETDEWEB)

    Zessin, Joerg [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany)]. E-mail: j.zessin@fz-rossendorf.de; Deuther-Conrad, Winnie [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Kretzschmar, Marion [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Wuest, Frank [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Pawelke, Beate [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Brust, Peter [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Steinbach, Joerg [Institut fuer Interdisziplinaere Isotopenforschung, 04318 Leipzig (Germany); Bergmann, Ralf [Institut fuer Bioanorganische und Radiopharmazeutische Chemie, Forschungszentrum Rossendorf, 01314 Dresden (Germany)

    2006-01-15

    N,N-Dimethyl-2-(2-amino-4-methylthiophenylthio)benzylamine (S Me-Adam, 1) is a highly potent and selective inhibitor of the serotonin transporter (SPERT). This compound was labeled with carbon-11 by methylation of the S-desmethyl precursor 10 with [{sup 11}C]methyl iodide to obtain the potential positron emission tomography (PET) radioligand [{sup 11}C]S Me-Adam. The radiochemical yield was 27{+-}5%, and the specific radioactivity was 26-40 GBq/{mu}mol at the end of synthesis. Ex vivo and in vivo biodistribution experiments in rats demonstrated a rapid accumulation of the radiotracer in brain regions known to be rich in SPERT, such as the thalamus/hypothalamus region (3.59{+-}0.41%ID/g at 5 min after injection). The specific uptake reached a thalamus to cerebellum ratio of 6.74{+-}0.95 at 60 min postinjection. The [{sup 11}C]SMe-ADAM uptake in the thalamus was significantly decreased by pretreatment with fluoxetine to 38{+-}11% of the control value. Furthermore, no metabolites of [{sup 11}C]SMe-ADAM could be detected in the SERT-rich regions of the rat brain. It is concluded that [{sup 11}C]SMe-ADAM may be a suitable PET ligand for SERT imaging in the living brain.

  9. A review of imaging agent development.

    Science.gov (United States)

    Agdeppa, Eric D; Spilker, Mary E

    2009-06-01

    This educational review highlights the processes, opportunities, and challenges encountered in the discovery and development of imaging agents, mainly positron emission tomography and single-photon emission computed tomography tracers. While the development of imaging agents parallels the drug development process, unique criteria are needed to identify opportunities for new agents. Imaging agent development has the flexibility to pursue functional or nonfunctional targets as long as they play a role in the specific disease or mechanism of interest and meet imageability requirements. However, their innovation is tempered by relatively small markets for diagnostic imaging agents, intellectual property challenges, radiolabeling constraints, and adequate target concentrations for imaging. At the same time, preclinical imaging is becoming a key translational tool for proof of mechanism and concept studies. Pharmaceutical and imaging industries face a common bottleneck in the form of the limited number of trials one company can possibly perform. However, microdosing and theranostics are evidence that partnerships between pharmaceutical and imaging companies can accelerate clinical translation of tracers and therapeutic interventions. This manuscript will comment on these aspects to provide an educational review of the discovery and development processes for imaging agents.

  10. The new PET imaging agent [{sup 11}C]AFE is a selective serotonin transporter ligand with fast brain uptake kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhihong [Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY 10032 (United States); Guo Ningning [Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY 10032 (United States); Narendran, Raj [Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY 10032 (United States)] [and others

    2004-11-01

    A new positron emission tomography (PET) radioligand for the serotonin transporter (SERT), [{sup 11}C]2-[2-[[(dimethylamino)methyl]phenyl]thio]-5-(2-fluoroethyl)phenylamine ([{sup 11}C]AFE, 12), was synthesized and evaluated in vivo in rats and baboons. [{sup 11}C]AFE (12) was prepared from its monomethylamino precursor 11 by reaction with high specific activity [{sup 11}C]methyl triflate. Radiochemical yield was 32{+-}17% based on [{sup 11}C]methyl triflate (n=6) and specific activity was 1670{+-}864 Ci/mmol at end of synthesis (EOS, n=6). Binding assays indicated that AFE displays high affinity for SERT (K{sub i}=1.80 nM for hSERT) and lower affinity for norepinephrine transporter (K{sub i}=946 nM for hNET) or dopamine transporter (K{sub i}>10,000 nM for hDAT). In addition, AFE displays negligible binding affinities for other serotonin and dopamine receptors, indicating an excellent binding selectivity in vitro. Biodistribution studies in rats indicated that [{sup 11}C]AFE enters the brain readily and localizes in regions known to contain high concentrations of SERT, such as the thalamus, hypothalamus, frontal cortex and striatum. Moreover, such binding in SERT-rich brain regions is reduced significantly by pretreatment with either citalopram or the cold compound itself, but not by nisoxetine or GBR 12935, thus demonstrating that [{sup 11}C]AFE binding in the rat brain is saturable, specific and selective for the SERT. Imaging experiments in baboons indicated that the uptake pattern of [{sup 11}C]AFE is consistent with the known distribution of SERT in the baboon brain, with high levels of radioactivity detected in the midbrain and thalamus, moderate levels in the hippocampus and striatum and low levels in the cortical regions. The uptake kinetics of [{sup 11}C]AFE in the baboon brain is rapid, with activity in the midbrain and thalamus peaking at 15-40 min postinjection. Pretreatment of the baboon with citalopram (4 mg/kg) 20 min before radioactivity injection

  11. Contrast Agent in Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Vu-Quang, Hieu

    2015-01-01

    Nanoparticles have been employed as contrast agent in magnetic resonance imaging (MRI) in order to improve sensitivity and accuracy in diagnosis. In addition, these contrast agents are potentially combined with other therapeutic compounds or near infrared bio-imaging (NIR) fluorophores to obtain...... theranostic or dual imaging purposes, respectively. There were two main types of MRI contrast agent that were synthesized during this PhD project including fluorine containing nanoparticles and magnetic nanoparticles. In regard of fluorine containing nanoparticles, there were two types contrast agent...... that were synthesized in project I and II. In project I, Poly (lactic-co-glycolic acid)-block-poly (ethylene glycol)-Folate Pefluorooctyl Bromide/Indocyanine green/ Doxorubicin (PLGA-PEG-Folate PFOB/ICG/Dox) has been formulated for the dual imaging NIR and 19F MRI as well as in the combination of Dox...

  12. ELSI Priorities for Brain Imaging

    OpenAIRE

    Illes, Judy; De Vries, Raymond; Cho, Mildred K.; Schraedley-Desmond, Pam

    2006-01-01

    As one of the most compelling technologies for imaging the brain, functional MRI (fMRI) produces measurements and persuasive pictures of research subjects making cognitive judgments and even reasoning through difficult moral decisions. Even after centuries of studying the link between brain and behavior, this capability presents a number of novel significant questions. For example, what are the implications of biologizing human experience? How might neuroimaging disrupt the mysteries of human...

  13. Synthesis and evaluation of [{sup 125}I]I-TSA as a brain nicotinic acetylcholine receptor {alpha}{sub 7} subtype imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Mikako [Laboratory of Genome Bio-Photonics, Photon Medical Research Center, Hamamatsu Medical University, Hamamatsu 431-3192 (Japan); Tatsumi, Ryo [Pharmaceuticals Research Unit, Research and Development Division, Mitsubishi Pharma Corporation, Yokohama 227-0033 (Japan); Fujio, Masakazu [Pharmaceuticals Research Unit, Research and Development Division, Mitsubishi Pharma Corporation, Yokohama 227-0033 (Japan); Katayama, Jiro [Pharmaceuticals Research Unit, Research and Development Division, Mitsubishi Pharma Corporation, Yokohama 227-0033 (Japan); Magata, Yasuhiro [Laboratory of Genome Bio-Photonics, Photon Medical Research Center, Hamamatsu Medical University, Hamamatsu 431-3192 (Japan)]. E-mail: magata@hama-med.ac.jp

    2006-04-15

    Introduction: Some in vitro investigations have suggested that the nicotinic acetylcholine receptor (nAChR) {alpha}{sub 7} subtype is implicated in Alzheimer's disease, schizophrenia and others. Recently, we developed (R)-3'-(5-bromothiophen-2-yl)spiro[1-azabicyclo[2.2.2]octane-3,5'-[1',3'] oxazolidin]-2'-one (Br-TSA), which has a high affinity and selectivity for {alpha}{sub 7} nAChRs. Therefore we synthesized (R)-3'-(5-[{sup 125}I]iodothiophen-2-yl)spiro[1-azabicyclo[2.2.2]octane-3,5'- [1',3']oxazolidin]-2'-one ([{sup 125}I]I-TSA) and evaluated its potential for the in vivo detection of {alpha}{sub 7} nAChR in brain. Methods: In vitro binding affinity of I-TSA was measured in rat brain homogenates. Radioiodination was accomplished by a Br-I exchange reaction. Biodistribution studies were undertaken in mice by tail vein injection of [{sup 125}I]I-TSA. In vivo receptor blocking studies were carried out by treating mice with methyllycaconitine (MLA; 5 nmol/5 {mu}l, i.c.v.) or nonradioactive I-TSA (50 {mu}mol/kg, i.v.). Results: I-TSA exhibited a high affinity and selectivity for the {alpha}{sub 7} nAChR (K {sub i} for {alpha}{sub 7} nAChR=0.54 nM). Initial uptake in the brain was high (4.42 %dose/g at 5 min), and the clearance of radioactivity was relatively slow in the hippocampus ({alpha}{sub 7} nAChR-rich region) and was rather rapid in the cerebellum ({alpha}{sub 7} nAChR poor region). The hippocampus to cerebellum uptake ratio was 0.9 at 5 min postinjection, but it was increased to 1.8 at 60 min postinjection. Although the effect was not statistically significant, administration of I-TSA and MLA decreased the accumulation of radioactivity in hippocampus. Conclusion: Despite its high affinity and selectivity, [{sup 125}I]I-TSA does not appear to be a suitable tracer for in vivo {alpha}{sub 7} nAChR receptor imaging studies due to its high nonspecific binding. Further structural optimization is needed.

  14. Historical Perspective of Imaging Contrast Agents.

    Science.gov (United States)

    Zamora, Carlos A; Castillo, Mauricio

    2017-11-01

    Contrast agents were introduced early in the history of medical imaging. Iodine-based intravascular agents became the radiographic compounds of choice and refinements of their chemical structures led to the highly tolerated low-osmolarity agents in use today. Gadolinium became the most popular compound for MR imaging; however, recognition of nephrogenic systemic fibrosis and in vivo dechelation intensified research on their safety profile. Ultrasonography contrast media evolved from manual injections of air through agitated saline solutions to microbubbles with different gases. Research has concentrated on bubble stabilization and development of small but sufficiently echogenic particles. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Functional Brain Imaging: A Comprehensive Survey

    CERN Document Server

    Sarraf, Saman

    2016-01-01

    Functional brain imaging allows measuring dynamic functionality in all brain regions. It is broadly used in clinical cognitive neuroscience as, well as in research. It will allow the observation of neural activities in the brain simultaneously. From the beginning when functional brain imaging was initiated by the mapping of brain functions proposed by phrenologists, many scientists were asking why we need to image brain functionality since we have already structural information. Simply, their important question was including a great answer. Functional information of the human brain would definitely complement structural information, helping to have a better understanding of what is happening in the brain. This paper, which could be useful to those who have an interest in functional brain imaging, such as engineers, will present a quick review of modalities used in functional brain imaging. We will concentrate on the most used techniques in functional imaging which are functional magnetic resonance imaging (fM...

  16. Brain Imaging Findings in Dyslexia

    Directory of Open Access Journals (Sweden)

    Ying-Fang Sun

    2010-04-01

    Full Text Available Dyslexia is a brain-based disorder that has been intensively studied in the Western world for more than a century because of its social burden. However, affected individuals in Chinese communities are neither recognized nor formally diagnosed. Previous studies have concentrated on the disadvantages of reading deficits, and few have addressed non-linguistic skills, which are included in the symptoms. In addition, certain dyslexics possess visual spatial talents that have usually been ignored. In this review, we discuss the available information regarding brain imaging studies of dyslexia based on studies in Caucasian subjects. Gray matter deficits have been demonstrated in dyslexics using structural magnetic resonance imaging. Reduced neural activities in the left temporal and left parietal cortices, and diffuse widespread activation patterns in the cerebellum could be detected using functional magnetic resonance imaging. Changes in lactate levels, N-acetylaspartate/choline-containing compounds and N-acetylaspartate/creatine ratios, and phosphomonoester peak area were detected in magnetic resonance spectroscopy studies. Lower fractional aniso tropy values in bilateral white matter tracts have been demonstrated by diffusion tensor imaging. Abnormal Broca's area activation was found using positron emission tomography imaging. Increased activities in the right frontal and temporal brain regions were detected using electroencephalography. Reduced hemispheric asymmetry and increased left inferior frontal activation were reported following magnetoencephalography. Although these imaging modalities are not currently diagnostic or prognostic, they are able to provide information on the causes of dyslexia beyond what was previously provided by behavioral or cognition studies.

  17. Studies of the retention mechanism of the brain perfusion imaging agent {sup 99m}{Tc}-bicisate ({sup 99m}{Tc}-ECD)

    Energy Technology Data Exchange (ETDEWEB)

    Walovitch, R.C.; Cheesman, E.H.; Maheu, L.J.; Hall, K.M. [DuPont Merck Pharmaceutical Co., North Billerica, MA (United States)

    1994-01-01

    The structure-activity relationship in a series of analogues of {sup 99m}{Tc}-bicisate ({sup 99m}{Tc}-N,N{prime}-1,2-ethylene-diylbis-L-cysteine diethyl ester dihydrochloride, RP-217) is described using in vivo studies in rodent and primate brain tissue. All analogues investigated were {sup 99m}{Tc}-diamine dithiol diesters, which were neutral and lipophilic and had modified brain uptake indexes ({ge}40) suggesting adequate first-pass extraction. All analogues were poorly retained by the rodent brain. In contrast, the stereochemistry and structure of the {sup 99m}{Tc}-complexes affected their brain retention in primates. All compounds that demonstrated selective primate brain retention were L-diesters that were metabolized in primate brain tissue to nonlypophilic complexes resulted from ester hydrolysis. Unretained complexes were not metabolized in primate brain tissue. More extensive studies were performed with {sup 99m}{Tc}-bicisate, which demonstrated poor brain retention in several nonprimate species (i.e., dogs, ferrets, pigs, and rodents). In rodent and nonhuman primate tissue, {sup 99m}{Tc}-bicisate was rapidly metabolized to a monoacid ester ({sup 99m}{Tc}-N,N{prime}-1,2-ethylenediylbis-L-cysteine monoethyl ester). Therefore, brain metabolism of {sup 99m}{Tc}-bicisate results in the formation of an acid product(s) that is selectively trapped in primate brain. 20 refs., 2 figs., 4 tabs.

  18. Multimodal nanoparticle imaging agents: design and applications

    Science.gov (United States)

    Burke, Benjamin P.; Cawthorne, Christopher; Archibald, Stephen J.

    2017-10-01

    Molecular imaging, where the location of molecules or nanoscale constructs can be tracked in the body to report on disease or biochemical processes, is rapidly expanding to include combined modality or multimodal imaging. No single imaging technique can offer the optimum combination of properties (e.g. resolution, sensitivity, cost, availability). The rapid technological advances in hardware to scan patients, and software to process and fuse images, are pushing the boundaries of novel medical imaging approaches, and hand-in-hand with this is the requirement for advanced and specific multimodal imaging agents. These agents can be detected using a selection from radioisotope, magnetic resonance and optical imaging, among others. Nanoparticles offer great scope in this area as they lend themselves, via facile modification procedures, to act as multifunctional constructs. They have relevance as therapeutics and drug delivery agents that can be tracked by molecular imaging techniques with the particular development of applications in optically guided surgery and as radiosensitizers. There has been a huge amount of research work to produce nanoconstructs for imaging, and the parameters for successful clinical translation and validation of therapeutic applications are now becoming much better understood. It is an exciting time of progress for these agents as their potential is closer to being realized with translation into the clinic. The coming 5-10 years will be critical, as we will see if the predicted improvement in clinical outcomes becomes a reality. Some of the latest advances in combination modality agents are selected and the progression pathway to clinical trials analysed. This article is part of the themed issue 'Challenges for chemistry in molecular imaging'.

  19. Minireview of Stereoselective Brain Imaging

    DEFF Research Database (Denmark)

    Smith, Donald F.; Jakobsen, Steen

    2014-01-01

    Stereoselectivity is a fundamental principle in living systems. Stereoselectivity reflects the dependence of molecular processes on the spatial orientation of constituent atoms. Stereoselective processes govern many aspects of brain function and direct the course of many psychotropic drugs. Today......, modern imaging techniques such as SPECT and PET provide a means for studying stereoselective processes in the living brain. Chemists have prepared numerous radiolabelled stereoisomers for use in SPECT and PET in order to explore various molecular processes in the living brain of anesthetized laboratory...... animals and awake humans. The studies have demonstrated how many aspects of neurotransmission consist of crucial stereoselective events that can affect brain function in health and disease. Here, we present a brief account of those findings in hope of stimulating further interest in the vital topic....

  20. High Framerate Imaging of Ultrasound Contrast Agents

    OpenAIRE

    Viti, Jacopo

    2016-01-01

    markdownabstractUltrasound contrast agents (UCAs) consists of a suspension of tiny gas bubbles that is injected into a patient's bloodstream to enhance the visualization of blood in ultrasound images. As UCAs respond differently to ultrasound pulses compared to the surrounding soft tissues and blood, it is possible to employ specialized techniques to identify and isolate UCAs in an ultrasound image. This is commonly referred to as Ultrasound Contrast Imaging. This PhD thesis evaluates several...

  1. Magnetic Resonance Imaging (MRI): Brain (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Brain KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Brain What's in this article? What It ...

  2. Liposome imaging agents in personalized medicine

    DEFF Research Database (Denmark)

    Petersen, Anncatrine Luisa; Hansen, Anders Elias; Gabizon, Alberto

    2012-01-01

    that selectively localize in tumor tissue can transport both drugs and imaging agents, which allows for a theranostic approach with great potential in personalized medicine. Radiolabeling of liposomes have for many years been used in preclinical studies for evaluating liposome in vivo performance and has been...... an important tool in the development of liposomal drugs. However, advanced imaging systems now provide new possibilities for non-invasive monitoring of liposome biodistribution in humans. Thus, advances in imaging and developments in liposome radiolabeling techniques allow us to enter a new arena where we...... start to consider how to use imaging for patient selection and treatment monitoring in connection to nanocarrier based medicines. Nanocarrier imaging agents could furthermore have interesting properties for disease diagnostics and staging. Here, we review the major advances in the development...

  3. Brain Imaging in Alzheimer Disease

    Science.gov (United States)

    Johnson, Keith A.; Fox, Nick C.; Sperling, Reisa A.; Klunk, William E.

    2012-01-01

    Imaging has played a variety of roles in the study of Alzheimer disease (AD) over the past four decades. Initially, computed tomography (CT) and then magnetic resonance imaging (MRI) were used diagnostically to rule out other causes of dementia. More recently, a variety of imaging modalities including structural and functional MRI and positron emission tomography (PET) studies of cerebral metabolism with fluoro-deoxy-d-glucose (FDG) and amyloid tracers such as Pittsburgh Compound-B (PiB) have shown characteristic changes in the brains of patients with AD, and in prodromal and even presymptomatic states that can help rule-in the AD pathophysiological process. No one imaging modality can serve all purposes as each have unique strengths and weaknesses. These modalities and their particular utilities are discussed in this article. The challenge for the future will be to combine imaging biomarkers to most efficiently facilitate diagnosis, disease staging, and, most importantly, development of effective disease-modifying therapies. PMID:22474610

  4. Imaging efficacy of a targeted imaging agent for fluorescence endoscopy

    Science.gov (United States)

    Healey, A. J.; Bendiksen, R.; Attramadal, T.; Bjerke, R.; Waagene, S.; Hvoslef, A. M.; Johannesen, E.

    2008-02-01

    Colorectal cancer is a major cause of cancer death. A significant unmet clinical need exists in the area of screening for earlier and more accurate diagnosis and treatment. We have identified a fluorescence imaging agent targeted to an early stage molecular marker for colorectal cancer. The agent is administered intravenously and imaged in a far red imaging channel as an adjunct to white light endoscopy. There is experimental evidence of preclinical proof of mechanism for the agent. In order to assess potential clinical efficacy, imaging was performed with a prototype fluorescence endoscope system designed to produce clinically relevant images. A clinical laparoscope system was modified for fluorescence imaging. The system was optimised for sensitivity. Images were recorded at settings matching those expected with a clinical endoscope implementation (at video frame rate operation). The animal model was comprised of a HCT-15 xenograft tumour expressing the target at concentration levels expected in early stage colorectal cancer. Tumours were grown subcutaneously. The imaging agent was administered intravenously at a dose of 50nmol/kg body weight. The animals were killed 2 hours post administration and prepared for imaging. A 3-4mm diameter, 1.6mm thick slice of viable tumour was placed over the opened colon and imaged with the laparoscope system. A receiver operator characteristic analysis was applied to imaging results. An area under the curve of 0.98 and a sensitivity of 87% [73, 96] and specificity of 100% [93, 100] were obtained.

  5. Imaging the Addicted Brain: Alcohol.

    Science.gov (United States)

    Dupuy, M; Chanraud, S

    2016-01-01

    Alcohol use disorder (AUD) represents a major public health issue due to its prevalence and severe health consequences. It may affect several aspects of an individual's life including work and relationships, and it also increases risk for additional problems such as brain injury. The causes and outcomes of AUD are varied; thus, attempting to understand this complex phenomenon requires investigation from multiple perspectives. Magnetic resonance imaging (MRI) is a powerful means to investigate brain anatomical and functional alterations related to AUD. Recent advances in MRI methods allow better investigation of the alterations to structural and functional brain networks in AUD. Here, we focus on findings from studies using multiple MRI techniques, which converge to support the considerable vulnerability of frontal systems. Indeed, MRI studies provide evidence for a "disconnection syndrome" which could be involved in the poor behavioral control observed in AUD. © 2016 Elsevier Inc. All rights reserved.

  6. Fueling and Imaging Brain Activation

    Directory of Open Access Journals (Sweden)

    Gerald A Dienel

    2012-05-01

    Full Text Available Metabolic signals are used for imaging and spectroscopic studies of brain function and disease and to elucidate the cellular basis of neuroenergetics. The major fuel for activated neurons and the models for neuron–astrocyte interactions have been controversial because discordant results are obtained in different experimental systems, some of which do not correspond to adult brain. In rats, the infrastructure to support the high energetic demands of adult brain is acquired during postnatal development and matures after weaning. The brain's capacity to supply and metabolize glucose and oxygen exceeds demand over a wide range of rates, and the hyperaemic response to functional activation is rapid. Oxidative metabolism provides most ATP, but glycolysis is frequently preferentially up-regulated during activation. Underestimation of glucose utilization rates with labelled glucose arises from increased lactate production, lactate diffusion via transporters and astrocytic gap junctions, and lactate release to blood and perivascular drainage. Increased pentose shunt pathway flux also causes label loss from C1 of glucose. Glucose analogues are used to assay cellular activities, but interpretation of results is uncertain due to insufficient characterization of transport and phosphorylation kinetics. Brain activation in subjects with low blood-lactate levels causes a brain-to-blood lactate gradient, with rapid lactate release. In contrast, lactate flooding of brain during physical activity or infusion provides an opportunistic, supplemental fuel. Available evidence indicates that lactate shuttling coupled to its local oxidation during activation is a small fraction of glucose oxidation. Developmental, experimental, and physiological context is critical for interpretation of metabolic studies in terms of theoretical models.

  7. High Framerate Imaging of Ultrasound Contrast Agents

    NARCIS (Netherlands)

    J. Viti (Jacopo)

    2016-01-01

    markdownabstractUltrasound contrast agents (UCAs) consists of a suspension of tiny gas bubbles that is injected into a patient's bloodstream to enhance the visualization of blood in ultrasound images. As UCAs respond differently to ultrasound pulses compared to the surrounding soft tissues and

  8. Development of [F-18]-Labeled Amyloid Imaging Agents for PET

    Energy Technology Data Exchange (ETDEWEB)

    Mathis, CA

    2007-05-09

    The applicant proposes to design and synthesize a series of fluorine-18-labeled radiopharmaceuticals to be used as amyloid imaging agents for positron emission tomography (PET). The investigators will conduct comprehensive iterative in vitro and in vivo studies based upon well defined acceptance criteria in order to identify lead agents suitable for human studies. The long term goals are to apply the selected radiotracers as potential diagnostic agents of Alzheimer's disease (AD), as surrogate markers of amyloid in the brain to determine the efficacy of anti-amyloid therapeutic drugs, and as tools to help address basic scientific questions regarding the progression of the neuropathology of AD, such as testing the "amyloid cascade hypothesis" which holds that amyloid accumulation is the primary cause of AD.

  9. Imaging brain development: the adolescent brain.

    Science.gov (United States)

    Blakemore, Sarah-Jayne

    2012-06-01

    The past 15 years have seen a rapid expansion in the number of studies using neuroimaging techniques to investigate maturational changes in the human brain. In this paper, I review MRI studies on structural changes in the developing brain, and fMRI studies on functional changes in the social brain during adolescence. Both MRI and fMRI studies point to adolescence as a period of continued neural development. In the final section, I discuss a number of areas of research that are just beginning and may be the subject of developmental neuroimaging in the next twenty years. Future studies might focus on complex questions including the development of functional connectivity; how gender and puberty influence adolescent brain development; the effects of genes, environment and culture on the adolescent brain; development of the atypical adolescent brain; and implications for policy of the study of the adolescent brain. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Functional brain imaging; Funktionelle Hirnbildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Gizewski, E.R. [Medizinische Universitaet Innsbruck, Universitaetsklinik fuer Neuroradiologie, Innsbruck (Austria)

    2016-02-15

    Functional magnetic resonance imaging (fMRI) is a non-invasive method that has become one of the major tools for understanding human brain function and in recent years has also been developed for clinical applications. Changes in hemodynamic signals correspond to changes in neuronal activity with good spatial and temporal resolution in fMRI. Using high-field MR systems and increasingly dedicated statistics and postprocessing, activated brain areas can be detected and superimposed on anatomical images. Currently, fMRI data are often combined in multimodal imaging, e. g. with diffusion tensor imaging (DTI) sequences. This method is helping to further understand the physiology of cognitive brain processes and is also being used in a number of clinical applications. In addition to the blood oxygenation level-dependent (BOLD) signals, this article deals with the construction of fMRI investigations, selection of paradigms and evaluation in the clinical routine. Clinically, this method is mainly used in the planning of brain surgery, analyzing the location of brain tumors in relation to eloquent brain areas and the lateralization of language processing. As the BOLD signal is dependent on the strength of the magnetic field as well as other limitations, an overview of recent developments is given. Increases of magnetic field strength (7 T), available head coils and advances in MRI analytical methods have led to constant improvement in fMRI signals and experimental design. Especially the depiction of eloquent brain regions can be done easily and quickly and has become an essential part of presurgical planning. (orig.) [German] Mittlerweile ist die funktionelle MRT (fMRT) eine Methode, die nicht mehr nur in der neurowissenschaftlichen Routine verwendet wird. Die fMRT ermoeglicht die nichtinvasive Darstellung der Hirnaktivitaet in guter raeumlicher und zeitlicher Aufloesung unter Ausnutzung der Durchblutungsaenderung aufgrund der erhoehten Nervenzellaktivitaet. Unter

  11. Elemental imaging of MRI contrast agents: benchmarking of LA-ICP-MS to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, J.A.T. [University of Sheffield, Centre for Analytical Sciences, Sheffield (United Kingdom); University of Sheffield, Department of Chemical and Biological Engineering, Sheffield (United Kingdom); Cox, A.G.; McLeod, C.W. [University of Sheffield, Centre for Analytical Sciences, Sheffield (United Kingdom); Bunch, J. [University of Birmingham, School of Chemistry, Birmingham (United Kingdom); Writer, M.J.; Hart, S.L. [UCL Institute of Child Health, Wolfson Centre for Gene Therapy of Childhood Disease, London (United Kingdom); Bienemann, A.; White, E. [University of Bristol, School of Clinical Sciences, Southmead Hospital, Bristol (United Kingdom); Bell, J. [Hammersmith Hospital, Metabolic and Molecular Imaging Group, MRC Clinical Sciences Centre, Imperial College London, London (United Kingdom)

    2012-06-15

    Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been used to map the spatial distribution of magnetic resonance imaging (MRI) contrast agents (Gd-based) in histological sections in order to explore synergies with in vivo MRI. Images from respective techniques are presented for two separate studies namely (1) convection enhanced delivery of a Gd nanocomplex (developmental therapeutic) into rat brain and (2) convection enhanced delivery, with co-infusion of Magnevist (commercial Gd contrast agent) and Carboplatin (chemotherapy drug), into pig brain. The LA technique was shown to be a powerful compliment to MRI not only in offering improved sensitivity, spatial resolution and signal quantitation but also in giving added value regarding the fate of administered agents (Gd and Pt agents). Furthermore simultaneous measurement of Fe enabled assignment of an anomalous contrast enhancement region in rat brain to haemorrhage at the infusion site. (orig.)

  12. Effects of anesthetic agents on brain blood oxygenation level revealed with ultra-high field MRI.

    Directory of Open Access Journals (Sweden)

    Luisa Ciobanu

    Full Text Available During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T(2*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7T and 17.2T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine. We showed that the brain/vessels contrast in T(2*-weighted images at 17.2T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation.

  13. Return Migration After Brain Drain: An Agent Based Simulation Approach

    CERN Document Server

    Biondo, A E; Rapisarda, A

    2012-01-01

    The Brain Drain phenomenon is particularly heterogeneous and is characterized by peculiar specifications. It influences the economic fundamentals of both the country of origin and the host one in terms of human capital accumulation. Here, the brain drain is considered from a microeconomic perspective: more precisely we focus on the individual rational decision to return, referring it to the social capital owned by the worker. The presented model, restricted to the case of academic personnel, compares utility levels to justify agent's migration conduct and to simulate several scenarios with a NetLogo agent based model. In particular, we developed a simulation framework based on two fundamental individual features, i.e. risk aversion and initial expectation, which characterize the dynamics of different agents according to the random evolution of their personal social networks. Our main result is that, according to the value of risk aversion and initial expectation, the probability of return migration depends on...

  14. Structural Magnetic Resonance Imaging of the Adolescent Brain

    National Research Council Canada - National Science Library

    GIEDD, JAY N

    2004-01-01

    A bstract : Magnetic resonance imaging (MRI) provides accurate anatomical brain images without the use of ionizing radiation, allowing longitudinal studies of brain morphometry during adolescent development...

  15. Imaging brain microstructure with diffusion MRI

    DEFF Research Database (Denmark)

    Alexander, Daniel C; Dyrby, Tim B; Nilsson, Markus

    2018-01-01

    This article gives an overview of microstructure imaging of the brain with diffusion MRI and reviews the state of the art. The microstructure-imaging paradigm aims to estimate and map microscopic properties of tissue using a model that links these properties to the voxel scale MR signal. Imaging...

  16. Advances in CNS Imaging Agents: Focus on PET and SPECT Tracers in Experimental and Clinical Use.

    Science.gov (United States)

    George, Noble; Gean, Emily G; Nandi, Ayon; Frolov, Boris; Zaidi, Eram; Lee, Ho; Brašić, James R; Wong, Dean F

    2015-04-01

    The physiological functioning of the brain is not well-known in current day medicine and the pathologies of many neuropsychiatric disorders are still not yet fully understood. With our aging population and better life expectancies, it has become imperative to find better biomarkers for disease progression as well as receptor target engagements. In the last decade, these major advances in the field of molecular CNS imaging have been made available with tools such as functional magnetic resonance imaging (fMRI), magnetic resonance spectroscopy (MRS), single photon emission computed tomography (SPECT), and neuroreceptor-targeted positron emission tomography (PET). These tools have given researchers, pharmaceutical companies, and clinical physicians a better method of understanding CNS dysfunctions, and the ability to employ improved therapeutic agents. This review is intended to provide an update on brain imaging agents that are currently used in clinical and translational research toward treatment of CNS disorders. The review begins with amyloid and tau imaging, the former of which has at least three [(18)F] agents that have been recently approved and will soon be available for clinical use for specific indications in the USA and elsewhere. Other prevalent PET and SPECT neurotransmitter system agents, including those newly US FDA-approved imaging agents related to the dopaminergic system, are included. A review of both mature and potentially growing PET imaging agents, including those targeting serotonin and opiate receptor systems, is also provided.

  17. Brain's tumor image processing using shearlet transform

    Science.gov (United States)

    Cadena, Luis; Espinosa, Nikolai; Cadena, Franklin; Korneeva, Anna; Kruglyakov, Alexey; Legalov, Alexander; Romanenko, Alexey; Zotin, Alexander

    2017-09-01

    Brain tumor detection is well known research area for medical and computer scientists. In last decades there has been much research done on tumor detection, segmentation, and classification. Medical imaging plays a central role in the diagnosis of brain tumors and nowadays uses methods non-invasive, high-resolution techniques, especially magnetic resonance imaging and computed tomography scans. Edge detection is a fundamental tool in image processing, particularly in the areas of feature detection and feature extraction, which aim at identifying points in a digital image at which the image has discontinuities. Shearlets is the most successful frameworks for the efficient representation of multidimensional data, capturing edges and other anisotropic features which frequently dominate multidimensional phenomena. The paper proposes an improved brain tumor detection method by automatically detecting tumor location in MR images, its features are extracted by new shearlet transform.

  18. Consecutive acquisition of time-resolved contrast-enhanced MR angiography and perfusion MR imaging with added dose of gadolinium-based contrast agent aids diagnosis of suspected brain metastasis.

    Science.gov (United States)

    Tsuchiya, Kazuhiro; Aoki, Shigeki; Shimoji, Keigo; Mori, Harushi; Kunimatsu, Akira

    2013-01-01

    Time-resolved contrast-enhanced magnetic resonance (MR) angiography (TCMRA) and perfusion MR imaging (PWI) have been used to assess the hemodynamics of brain tumors. We assessed the feasibility and value of consecutive performance of these techniques to evaluate suspected brain metastasis following supplementary injection of gadolinium-based contrast medium. In 69 patients with suspected brain metastasis, we obtained precontrast MR images followed by TCMRA and postcontrast T1-weighted images after administration of 0.1 mmol/kg gadoteridol. When findings were negative or equivocal, we injected an additional 0.1-mmol/kg dose of gadoteridol and obtained PWI and second postcontrast T1-weighted images. We used a 3-point scale to grade perfusion maps and TCMRA and assessed whether these techniques added information to conventional MR imaging in the differential diagnosis. We also evaluated whether the second contrast injection improved the conspicuity and/or number of enhancing lesions and used a 4-point scoring system to quantitatively analyze diagnostic yield of TCMRA and PWI. We could assess tumor hemodynamics on PWI maps and TCMRA images in all 69 patients. In 14 cases (20%), PWI and/or TCMRA added information to conventional MR findings. After second injection of contrast medium, lesion conspicuity improved in 58 of the 69 cases (84%), and the number of detected lesions increased in 11 of 31 cases diagnosed with metastatic disease (36%). Quantitative analysis revealed TCMRA and PWI provided significant additional diagnostic information (Kruskal-Wallis test, PPWI using supplementary contrast injection can facilitate differential diagnosis of suspected brain metastasis and improve the number and conspicuity of detected lesions.

  19. Classification and basic properties of contrast agents for magnetic resonance imaging.

    Science.gov (United States)

    Geraldes, Carlos F G C; Laurent, Sophie

    2009-01-01

    A comprehensive classification of contrast agents currently used or under development for magnetic resonance imaging (MRI) is presented. Agents based on small chelates, macromolecular systems, iron oxides and other nanosystems, as well as responsive, chemical exchange saturation transfer (CEST) and hyperpolarization agents are covered in order to discuss the various possibilities of using MRI as a molecular imaging technique. The classification includes composition, magnetic properties, biodistribution and imaging applications. Chemical compositions of various classes of MRI contrast agents are tabulated, and their magnetic status including diamagnetic, paramagnetic and superparamagnetic are outlined. Classification according to biodistribution covers all types of MRI contrast agents including, among others, extracellular, blood pool, polymeric, particulate, responsive, oral, and organ specific (hepatobiliary, RES, lymph nodes, bone marrow and brain). Various targeting strategies of molecular, macromolecular and particulate carriers are also illustrated. Copyright 2009 John Wiley & Sons, Ltd.

  20. Development of Tc-99m Imaging Agents for Abeta Plaques

    Energy Technology Data Exchange (ETDEWEB)

    Zhi-Ping, Zhuang; Mei-Ping Kung; Catherihne Hou; Hank F. Kung

    2008-09-26

    Development of SPECT imaging agents based on Tc-99m targeting Aβ plaques is useful for diagnosis of Alzheimer’s disease (AD). A stilbene derivative, [11C]SB-13, showing promise in detecting senile plaques present in AD patients has been reported previously1,2. Based on the 4’-amino-stilbene core structure we have added substituted groups through which a chelating group, N2S2, was conjugated. We report herein a series of Tc-99m labeled stilbene derivative conjugated with a TcO[N2S2] core. The syntheses of stilbenes containing a N2S2 chelating ligand are achieved by a scheme shown. Lipophilic 99mTc stilbene complexes were successfully prepared and purified through HPLC. Preliminary results of in vitro labeling of brain sections from transgenic mice showed very promising plaque labeling. These 99mTc stilbene derivatives are warranted for further evaluations as potential imaging agents targeting amyloid plaques.

  1. Imaging Brain Development: Benefiting from Individual Variability

    Directory of Open Access Journals (Sweden)

    Megha Sharda

    2015-01-01

    Full Text Available Human brain development is a complex process that evolves from early childhood to young adulthood. Major advances in brain imaging are increasingly being used to characterize the developing brain. These advances have further helped to elucidate the dynamic maturational processes that lead to the emergence of complex cognitive abilities in both typical and atypical development. However, conventional approaches involve categorical group comparison models and tend to disregard the role of widespread interindividual variability in brain development. This review highlights how this variability can inform our understanding of developmental processes. The latest studies in the field of brain development are reviewed, with a particular focus on the role of individual variability and the consequent heterogeneity in brain structural and functional development. This review also highlights how such heterogeneity might be utilized to inform our understanding of complex neuropsychiatric disorders and recommends the use of more dimensional approaches to study brain development.

  2. Conjugation of functionalized SPIONs with transferrin for targeting and imaging brain glial tumors in rat model.

    Directory of Open Access Journals (Sweden)

    Weili Jiang

    Full Text Available Currently, effective and specific diagnostic imaging of brain glioma is a major challenge. Nanomedicine plays an essential role by delivering the contrast agent in a targeted manner to specific tumor cells, leading to improvement in accurate diagnosis by good visualization and specific demonstration of tumor cells. This study investigated the preparation and characterization of a targeted MR contrast agent, transferrin-conjugated superparamagnetic iron oxide nanoparticles (Tf-SPIONs, for brain glioma detection. MR imaging showed the obvious contrast change of brain glioma before and after administration of Tf-SPIONs in C6 glioma rat model in vivo on T2 weighted imaging. Significant contrast enhancement of brain glioma could still be clearly seen even 48 h post injection, due to the retention of Tf-SPIONs in cytoplasm of tumor cells which was proved by Prussian blue staining. Thus, these results suggest that Tf-SPIONs could be a potential targeting MR contrast agent for the brain glioma.

  3. Manganese accumulation in the brain: MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, A.; Nomiyama, K.; Takase, Y.; Nakazono, T.; Nojiri, J.; Kudo, S. [Saga Medical School, Department of Radiology, Saga (Japan); Noguchi, T. [Kyushu University, Department of Clinical Radiology, Graduate School of Medicine, Fukuoka (Japan)

    2007-09-15

    Manganese (Mn) accumulation in the brain is detected as symmetrical high signal intensity in the globus pallidi on T1-weighted MR images without an abnormal signal on T2-weighted images. In this review, we present several cases of Mn accumulation in the brain due to acquired or congenital diseases of the abdomen including hepatic cirrhosis with a portosystemic shunt, congenital biliary atresia, primary biliary cirrhosis, congenital intrahepatic portosystemic shunt without liver dysfunction, Rendu-Osler-Weber syndrome with a diffuse intrahepatic portosystemic shunt, and patent ductus venosus. Other causes of Mn accumulation in the brain are Mn overload from total parenteral nutrition and welding-related Mn intoxication. (orig.)

  4. Nootropic agents stimulate neurogenesis. Brain Cells, Inc.: WO2007104035.

    Science.gov (United States)

    Taupin, Philippe

    2009-05-01

    The application is in the field of adult neurogenesis, neural stem cells and cellular therapy. It aims to characterize the activity of nootropic agents on adult neurogenesis in vitro. Nootropic agents are substances improving cognitive and mental abilities. AMPA (alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate) and nootropic agents were assessed for the potential to differentiate human neural progenitor and stem cells into neuronal cells in vitro. They were also tested for their behavioural activity on the novel object recognition task. AMPA, piracetam, FK-960 and SGS-111 induce and stimulate neuronal differentiation of human-derived neural progenitor and stem cells. SGS-111 increases the number of visits to the novel object. The neurogenic activity of piracetam and SGS-111 is mediated through AMPA receptor. The neurogenic activity of SGS-111 may contribute and play a role in its nootropic activity. These results suggest that nootropic agents may elicit some of their effects through their neurogenic activity. The application claims the use of nootropic agents for their neurogenic activity and for the treatment of neurological diseases, disorders and injuries, by stimulating or increasing the generation of neuronal cells in the adult brain.

  5. PET/MRI for Oncologic Brain Imaging

    DEFF Research Database (Denmark)

    Rausch, Ivo; Rischka, Lucas; Ladefoged, Claes N

    2017-01-01

    by Siemens Healthcare). As a reference, AC maps were derived from patient-specific CT images (CTref). PET data were reconstructed using standard settings after AC with all 4 AC methods. We report changes in diagnosis for all brain tumor patients and the following relative differences values (RDs...... of the whole brain and 10 anatomic regions segmented on MR images.Results:For brain tumor imaging (A and B), the standard PET-based diagnosis was not affected by any of the 3 MR-AC methods. For A, the average RDs of SUVmeanwere -10%, -4%, and -3% and of the VOIs 1%, 2%, and 7% for DIXON, UTE, and BD......, respectively.Conclusion:The diagnostic reading of PET/MR patients with brain tumors did not change with the chosen AC method. Quantitative accuracy of SUVs was clinically acceptable for UTE- and BD-AC for group A, whereas for group B BD was in accordance with CTref. Nevertheless, for the quantification...

  6. Brain Imaging in Alzheimer Disease

    NARCIS (Netherlands)

    Johnson, K.A.; Fox, N.C.; Sperling, R.A.; Klunk, W.E.

    2012-01-01

    Imaging has played a variety of roles in the study of Alzheimer disease (AD) over the past four decades. Initially, computed tomography (CT) and then magnetic resonance imaging (MRI) were used diagnostically to rule out other causes of dementia. More recently, a variety of imaging modalities

  7. Advantages in functional imaging of the brain

    Directory of Open Access Journals (Sweden)

    Walter eMier

    2015-05-01

    Full Text Available As neuronal pathologies cause only minor morphological alterations, molecular imaging techniques are a prerequisite for the study of diseases of the brain. The development of molecular probes that specifically bind biochemical markers and the advances of instrumentation have revolutionized the possibilities to gain insight into the human brain organization and beyond this visualize structure-function and brain-behavior relationships. The review describes the development and current applications of functional brain imaging techniques with a focus on applications in psychiatry. A historical overview of the development of functional imaging is followed by the portrayal of the principles and applications of positron emission tomography (PET and functional magnetic resonance imaging (fMRI, two key molecular imaging techniques that have revolutionized the ability to image molecular processes in the brain. In the juxtaposition of PET and fMRI in hybrid PET/MRI scanners enhances the significance of both modalities for research in neurology and psychiatry and might pave the way for a new area of personalized medicine.

  8. Magnetic Resonance Imaging Contrast Agents: A Review of Literature

    Directory of Open Access Journals (Sweden)

    Zahra Sahraei

    2015-10-01

    Full Text Available  Magnetic Resonance Imaging (MRI contrast agents most commonly agents used in diagnosing different diseases. Several agents have been ever introduced with different peculiar characteristics. They vary in potency, adverse reaction and other specification, so it is important to select the proper agent in different situations. We conducted a systematic literature search in MEDLINE/PUBMED, Web of Science (ISI, Scopus,Google Scholar by using keywords "gadolinium" and "MRI contrast Medias", "Gadofosvest", "Gadobenate" and "Gadoxetate". The most frequent contrast media agents made based on gadolinium (Gd. These are divided into two categories based on the structure of their chelating parts, linear agents and macrocyclic agents. All characteristics of contrast media factors, including efficiency, kinetic properties, stability, side effects and the rate of resolution are directly related to the structure of chelating part of that formulation.In vitro data has shown that the macrocyclic compounds are the most stable Gd-CA as they do not bind to serum proteins, they all possess similar and relatively low relaxivity and the prevalence of Nephrogenic Systemic Fibrosis (NSF has decreased by increasing the use of macrocyclic agents in recent years. No cases of NSF have been recorded after the administration of any of the high-relaxivity protein interacting agents, the vascular imaging agent gadofosveset trisodium (Ablavar, the hepatic imaging agent gadoxetate meglumine (Eovist, and the multipurpose agent gadobenate dimeglumine (MultiHance. In pregnancy and lactating women, stable macrocyclic agent is recommended.

  9. Cranial nerve contrast using nerve-specific fluorophores improved by paired-agent imaging with indocyanine green as a control agent

    Science.gov (United States)

    Torres, Veronica C.; Vuong, Victoria D.; Wilson, Todd; Wewel, Joshua; Byrne, Richard W.; Tichauer, Kenneth M.

    2017-09-01

    Nerve preservation during surgery is critical because damage can result in significant morbidity. This remains a challenge especially for skull base surgeries where cranial nerves (CNs) are involved because visualization and access are particularly poor in that location. We present a paired-agent imaging method to enhance identification of CNs using nerve-specific fluorophores. Two myelin-targeting imaging agents were evaluated, Oxazine 4 and Rhodamine 800, and coadministered with a control agent, indocyanine green, either intravenously or topically in rats. Fluorescence imaging was performed on excised brains ex vivo, and nerve contrast was evaluated via paired-agent ratiometric data analysis. Although contrast was improved among all experimental groups using paired-agent imaging compared to conventional, solely targeted imaging, Oxazine 4 applied directly exhibited the greatest enhancement, with a minimum 3 times improvement in CNs delineation. This work highlights the importance of accounting for nonspecific signal of targeted agents, and demonstrates that paired-agent imaging is one method capable of doing so. Although staining, rinsing, and imaging protocols need to be optimized, these findings serve as a demonstration for the potential use of paired-agent imaging to improve contrast of CNs, and consequently, surgical outcome.

  10. CT and MR imaging diagnosis and staging of hepatocellular carcinoma: part II. Extracellular agents, hepatobiliary agents, and ancillary imaging features.

    Science.gov (United States)

    Choi, Jin-Young; Lee, Jeong-Min; Sirlin, Claude B

    2014-10-01

    Computed tomography (CT) and magnetic resonance (MR) imaging play critical roles in the diagnosis and staging of hepatocellular carcinoma (HCC). The second article of this two-part review discusses basic concepts of diagnosis and staging, reviews the diagnostic performance of CT and MR imaging with extracellular contrast agents and of MR imaging with hepatobiliary contrast agents, and examines in depth the major and ancillary imaging features used in the diagnosis and characterization of HCC. © RSNA, 2014.

  11. Brain imaging, genetics and emotion

    NARCIS (Netherlands)

    Aleman, Andre; Swart, Marte; van Rijn, Sophie

    This paper reviews the published evidence on genetically driven variation in neurotransmitter function and brain circuits involved in emotion. Several studies point to a role of the serotonin transporter promoter polymorphism in amygdala activation during emotion perception. We also discuss other

  12. Proton MRS imaging in pediatric brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Zarifi, Maria [Aghia Sophia Children' s Hospital, Department of Radiology, Athens (Greece); Tzika, A.A. [Harvard Medical School, Department of Surgery, Massachusetts General Hospital, Boston, MA (United States); Shriners Burn Hospital, Boston, MA (United States)

    2016-06-15

    Magnetic resonance (MR) techniques offer a noninvasive, non-irradiating yet sensitive approach to diagnosing and monitoring pediatric brain tumors. Proton MR spectroscopy (MRS), as an adjunct to MRI, is being more widely applied to monitor the metabolic aspects of brain cancer. In vivo MRS biomarkers represent a promising advance and may influence treatment choice at both initial diagnosis and follow-up, given the inherent difficulties of sequential biopsies to monitor therapeutic response. When combined with anatomical or other types of imaging, MRS provides unique information regarding biochemistry in inoperable brain tumors and can complement neuropathological data, guide biopsies and enhance insight into therapeutic options. The combination of noninvasively acquired prognostic information and the high-resolution anatomical imaging provided by conventional MRI is expected to surpass molecular analysis and DNA microarray gene profiling, both of which, although promising, depend on invasive biopsy. This review focuses on recent data in the field of MRS in children with brain tumors. (orig.)

  13. Brain 'imaging' in the Renaissance.

    Science.gov (United States)

    Paluzzi, Alessandro; Belli, Antonio; Bain, Peter; Viva, Laura

    2007-12-01

    During the Renaissance, a period of 'rebirth' for humanities and science, new knowledge and speculation began to emerge about the function of the human body, replacing ancient religious and philosophical dogma. The brain must have been a fascinating mystery to a Renaissance artist, but some speculation existed at that time on the function of its parts. Here we show how revived interest in anatomy and life sciences may have influenced the figurative work of Italian and Flemish masters, such as Rafael, Michelangelo and David. We present a historical perspective on the artists and the period in which they lived, their fascination for human anatomy and its symbolic use in their art. Prior to the 16th century, knowledge of the brain was limited and influenced in a dogmatic way by the teachings of Galen(1) who, as we now know, conducted his anatomical studies not on humans but on animals.(2) Nemesus, Bishop of Emesa, in around the year 400 was one of the first to attribute mental faculties to the brain, specifically to the ventricles. He identified two anterior (lateral) ventricles, to which he assigned perception, a middle ventricle responsible for cognition and a posterior ventricle for memory.(2,3) After a long period of stasis in the Middle Ages, Renaissance scholars realized the importance of making direct observations on dissected cadavers. Between 1504 and 1507, Leonardo da Vinci conducted experiments to reveal the anatomy of the ventricular system in the brain. He injected hot wax through a tube thrust into the ventricular cavities of an ox and then scraped the overlying brain off, thus obtaining, in a simple but ingenious way, an accurate cast of the ventricles.(2,4) Leonardo shared the belief promoted by scholarly Christians that the ventricles were the abode of rational soul. We have several examples of hidden symbolism in Renaissance paintings, but the influence of phrenology and this rudimentary knowledge of neuroanatomy on artists of that period is under

  14. IMAGING THE BRAIN AS SCHIZOPHRENIA DEVELOPS: DYNAMIC & GENETIC BRAIN MAPS.

    Science.gov (United States)

    Thompson, Paul; Rapoport, Judith L; Cannon, Tyrone D; Toga, Arthur W

    2002-01-01

    Schizophrenia is a chronic, debilitating psychiatric disorder that affects 0.2-2% of the population worldwide. Often striking without warning in the late teens or early twenties, its symptoms include auditory and visual hallucinations, psychotic outbreaks, bizarre or disordered thinking, depression and social withdrawal. To combat the disease, new antipsychotic drugs are emerging; these atypical neuroleptics target dopamine and serotonin pathways in the brain, offering increased therapeutic efficacy with fewer side effects. Despite their moderate success in controlling some patients' symptoms, little is known about the causes of schizophrenia, and what triggers the disease. Its peculiar age of onset raises key questions: What physical changes occur in the brain as a patient develops schizophrenia? Do these deficits spread in the brain, and can they be opposed? How do they relate to psychotic symptoms? As risk for the disease is genetically transmitted, do a patient's relatives exhibit similar brain changes? Recent advances in brain imaging and genetics provide exciting insight on these questions. Neuroimaging can now chart the emergence and progression of deficits in the brain, providing an exceptionally sharp scalpel to dissect the effects of genetic risk, environmental triggers, and susceptibility genes. Visualizing the dynamics of the disease, these techniques also offer new strategies to evaluate drugs that combat the unrelenting symptoms of schizophrenia.

  15. Formulations for Intranasal Delivery of Pharmacological Agents to Combat Brain Disease: A New Opportunity to Tackle GBM?

    Directory of Open Access Journals (Sweden)

    Stefaan W. van Gool

    2013-08-01

    Full Text Available Despite recent advances in tumor imaging and chemoradiotherapy, the median overall survival of patients diagnosed with glioblastoma multiforme does not exceed 15 months. Infiltration of glioma cells into the brain parenchyma, and the blood-brain barrier are important hurdles to further increase the efficacy of classic therapeutic tools. Local administration methods of therapeutic agents, such as convection enhanced delivery and intracerebral injections, are often associated with adverse events. The intranasal pathway has been proposed as a non-invasive alternative route to deliver therapeutics to the brain. This route will bypass the blood-brain barrier and limit systemic side effects. Upon presentation at the nasal cavity, pharmacological agents reach the brain via the olfactory and trigeminal nerves. Recently, formulations have been developed to further enhance this nose-to-brain transport, mainly with the use of nanoparticles. In this review, the focus will be on formulations of pharmacological agents, which increase the nasal permeation of hydrophilic agents to the brain, improve delivery at a constant and slow release rate, protect therapeutics from degradation along the pathway, increase mucoadhesion, and facilitate overall nasal transport. A mounting body of evidence is accumulating that the underexplored intranasal delivery route might represent a major breakthrough to combat glioblastoma.

  16. Formulations for Intranasal Delivery of Pharmacological Agents to Combat Brain Disease: A New Opportunity to Tackle GBM?

    Science.gov (United States)

    van Woensel, Matthias; Wauthoz, Nathalie; Rosière, Rémi; Amighi, Karim; Mathieu, Véronique; Lefranc, Florence; van Gool, Stefaan W.; de Vleeschouwer, Steven

    2013-01-01

    Despite recent advances in tumor imaging and chemoradiotherapy, the median overall survival of patients diagnosed with glioblastoma multiforme does not exceed 15 months. Infiltration of glioma cells into the brain parenchyma, and the blood-brain barrier are important hurdles to further increase the efficacy of classic therapeutic tools. Local administration methods of therapeutic agents, such as convection enhanced delivery and intracerebral injections, are often associated with adverse events. The intranasal pathway has been proposed as a non-invasive alternative route to deliver therapeutics to the brain. This route will bypass the blood-brain barrier and limit systemic side effects. Upon presentation at the nasal cavity, pharmacological agents reach the brain via the olfactory and trigeminal nerves. Recently, formulations have been developed to further enhance this nose-to-brain transport, mainly with the use of nanoparticles. In this review, the focus will be on formulations of pharmacological agents, which increase the nasal permeation of hydrophilic agents to the brain, improve delivery at a constant and slow release rate, protect therapeutics from degradation along the pathway, increase mucoadhesion, and facilitate overall nasal transport. A mounting body of evidence is accumulating that the underexplored intranasal delivery route might represent a major breakthrough to combat glioblastoma. PMID:24202332

  17. Mixed lanthanide oxide nanoparticles as dual imaging agent in biomedicine

    Science.gov (United States)

    Xu, Wenlong; Bony, Badrul Alam; Kim, Cho Rong; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong; Lee, Gang Ho

    2013-01-01

    There is no doubt that the molecular imaging is an extremely important technique in diagnosing diseases. Dual imaging is emerging as a step forward in molecular imaging technique because it can provide us with more information useful for diagnosing diseases than single imaging. Therefore, diverse dual imaging modalities should be developed. Molecular imaging generally relies on imaging agents. Mixed lanthanide oxide nanoparticles could be valuable materials for dual magnetic resonance imaging (MRI)-fluorescent imaging (FI) because they have both excellent and diverse magnetic and fluorescent properties useful for dual MRI-FI, depending on lanthanide ions used. Since they are mixed nanoparticles, they are compact, robust, and stable, which is extremely useful for biomedical applications. They can be also easily synthesized with facile composition control. In this study, we explored three systems of ultrasmall mixed lanthanide (Dy/Eu, Ho/Eu, and Ho/Tb) oxide nanoparticles to demonstrate their usefulness as dual T2 MRI–FI agents. PMID:24220641

  18. Dendrimer-based contrast agents for molecular imaging.

    Science.gov (United States)

    Longmire, Michelle; Choyke, Peter L; Kobayashi, Hisataka

    2008-01-01

    The extensive adaptability of dendrimer-based contrast agents is ideal for the molecular imaging of organs and other target-specific locations. The ability of literally atom-by-atom modification on cores, interiors, and surface groups, permits the rational manipulation of dendrimer-based agents in order to optimize their physical characteristics, biodistribution, receptor-mediated targeting, and controlled release of the payload. Such modifications enable agents to localize preferentially to areas or organs of interest for facilitating target-specific imaging as well as assume excretion pathways that do not interfere with desired applications. Recent innovations in dendrimer research have increased agent directibility and new synthetic chemistry approaches have increased efficiency of production as well as led to the creation of novel dendrimer-based contrast agents. In addition, by taking advantage of the numerous attachment sites available on the surface of a single dendrimer molecule, new synthetic chemistry techniques have led to the development of multi-modality magnetic resonance, radionuclide, and fluorescence imaging agents for molecular imaging. Herein we discuss advances in dendrimer-based contrast agents for molecular imaging focusing mainly on the chemical design as applied to optical, magnetic resonance, computer tomography, radionuclide, and multi-modality imaging.

  19. Automatic Synthesis and Micro PET/CT Imaging Study of 11C-DASB as a Serotonin Imaging Agent

    Directory of Open Access Journals (Sweden)

    ZHANG Xiao-jun

    2015-01-01

    Full Text Available Objectives: Automatic synthesis of 11C-DASB as a serotonin imaging agent was established and Micro PET/CT imaging with Wistar rat was performed. Methods: Optimization of 11C-DASB synthesis was established by modifying different 11C-methylation agents, solvent and reaction conditions. Automated procedure for the synthesis of 11C-DASB was established, and Micro PET/CT imaging was complied with Wistar rat. Results: The optimized 11C-DASB synthesis was obtained. When 11C-CH3-Triflate was used as methylation agent, 500 μL DMSO was used to dissolve 1 mg precursor, the reaction was carried out at 80 ℃ for 2 min, the radiochemical synthesis yield was 63.7%. Micro PET/CT studies in rat showed that the initial uptake of 11C-DASB in the brain was high, especially in region of the highest density of SERT, such as colliculus and mid brain. Conclusion: The study should provide the basis for routine preparations of 11C-DASB with high reliability, it may be useful for PET imaging of SERT binding sites in the brain.

  20. Imaging biomarkers in primary brain tumours

    Energy Technology Data Exchange (ETDEWEB)

    Lopci, Egesta; Chiti, Arturo [Humanitas Clinical and Research Center, Nuclear Medicine Department, Rozzano, MI (Italy); Franzese, Ciro; Navarria, Pierina; Scorsetti, Marta [Humanitas Clinical and Research Center, Radiosurgery and Radiotherapy, Rozzano, MI (Italy); Grimaldi, Marco [Humanitas Clinical and Research Center, Radiology, Rozzano, MI (Italy); Zucali, Paolo Andrea; Simonelli, Matteo [Humanitas Clinical and Research Center, Medical Oncology, Rozzano, MI (Italy); Bello, Lorenzo [Humanitas Clinical and Research Center, Neurosurgery, Rozzano, MI (Italy)

    2015-04-01

    We are getting used to referring to instrumentally detectable biological features in medical language as ''imaging biomarkers''. These two terms combined reflect the evolution of medical imaging during recent decades, and conceptually comprise the principle of noninvasive detection of internal processes that can become targets for supplementary therapeutic strategies. These targets in oncology include those biological pathways that are associated with several tumour features including independence from growth and growth-inhibitory signals, avoidance of apoptosis and immune system control, unlimited potential for replication, self-sufficiency in vascular supply and neoangiogenesis, acquired tissue invasiveness and metastatic diffusion. Concerning brain tumours, there have been major improvements in neurosurgical techniques and radiotherapy planning, and developments of novel target drugs, thus increasing the need for reproducible, noninvasive, quantitative imaging biomarkers. However, in this context, conventional radiological criteria may be inappropriate to determine the best therapeutic option and subsequently to assess response to therapy. Integration of molecular imaging for the evaluation of brain tumours has for this reason become necessary, and an important role in this setting is played by imaging biomarkers in PET and MRI. In the current review, we describe most relevant techniques and biomarkers used for imaging primary brain tumours in clinical practice, and discuss potential future developments from the experimental context. (orig.)

  1. Modelling Brain Tissue using Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Dyrby, Tim Bjørn

    2008-01-01

    Diffusion MRI, or diffusion weighted imaging (DWI), is a technique that measures the restricted diffusion of water molecules within brain tissue. Different reconstruction methods quantify water-diffusion anisotropy in the intra- and extra-cellular spaces of the neural environment. Fibre tracking...

  2. History and evolution of brain tumor imaging: insights through radiology.

    Science.gov (United States)

    Castillo, Mauricio

    2014-11-01

    This review recounts the history of brain tumor diagnosis from antiquity to the present and, indirectly, the history of neuroradiology. Imaging of the brain has from the beginning held an enormous interest because of the inherent difficulty of this endeavor due to the presence of the skull. Because of this, most techniques when newly developed have always been used in neuroradiology and, although some have proved to be inappropriate for this purpose, many were easily incorporated into the specialty. The first major advance in modern neuroimaging was contrast agent-enhanced computed tomography, which permitted accurate anatomic localization of brain tumors and, by virtue of contrast enhancement, malignant ones. The most important advances in neuroimaging occurred with the development of magnetic resonance imaging and diffusion-weighted sequences that allowed an indirect estimation of tumor cellularity; this was further refined by the development of perfusion and permeability mapping. From its beginnings with indirect and purely anatomic imaging techniques, neuroradiology now uses a combination of anatomic and physiologic techniques that will play a critical role in biologic tumor imaging and radiologic genomics.

  3. Theranostic agents for intracellular gene delivery with spatiotemporal imaging

    OpenAIRE

    Knipe, Jennifer M.; Peters, Jonathan T.; Peppas, Nicholas A.

    2013-01-01

    Gene therapy is the modification of gene expression to treat a disease. However, efficient intracellular delivery and monitoring of gene therapeutic agents is an ongoing challenge. Use of theranostic agents with suitable targeted, controlled delivery and imaging modalities has the potential to greatly advance gene therapy. Inorganic nanoparticles including magnetic nanoparticles, gold nanoparticles, and quantum dots have been shown to be effective theranostic agents for the delivery and spati...

  4. Brain imaging of affective disorders and schizophrenia.

    Science.gov (United States)

    Kishimoto, H; Yamada, K; Iseki, E; Kosaka, K; Okoshi, T

    1998-12-01

    We review recent findings in human brain imaging, for example, which brain areas are used during perception of colors, moving objects, human faces, facial expressions, sadness and happiness etc. One study used fluorine-18-labeled deoxyglucose positron emission tomography (PET) in patients with unipolar depression and bipolar depression, and found hypometabolism in the left anterolateral prefrontal cortex. Another study reported increased regional cerebral blood flow in the amygdala in familial pure depressive disease. Using 11C-glucose PET, we reported that the glutamic acid pool was reduced in cortical areas of the brain in patients with major depression. We also found that the thalamic and cingulate areas were hyperactive in drug-naive (never medicated) acute schizophrenics, while the associative frontal, parietal, temporal gyri were hypoactive in drug-naive chronic schizophrenics. Brain biochemical disturbances of schizophrenic patients involved glutamic acid, N-acetyl aspartic acid, phosphatidylcholine and sphingomyelin which are important chemical substances in the working brain. The areas of the thalamus and the cingulate which become hyperactive in acute schizophrenic patients are important brain areas for perception and communication. The association areas of the cortex which become disturbed in chronic schizophrenia are essential brain areas in human creativity (language, concepts, formation of cultures and societies) and exist only in human beings.

  5. Chitosan-based formulations of drugs, imaging agents and biotherapeutics

    NARCIS (Netherlands)

    Amidi, M.; Hennink, W.E.

    This preface is part of the Advanced Drug Delivery Reviews theme issue on “Chitosan-Based Formulations of Drugs, Imaging Agents and Biotherapeutics”. This special Advanced Drug Delivery Reviews issue summarizes recent progress and different applications of chitosanbased formulations.

  6. Multimodal Imaging Brain Connectivity Analysis (MIBCA toolbox

    Directory of Open Access Journals (Sweden)

    Andre Santos Ribeiro

    2015-07-01

    Full Text Available Aim. In recent years, connectivity studies using neuroimaging data have increased the understanding of the organization of large-scale structural and functional brain networks. However, data analysis is time consuming as rigorous procedures must be assured, from structuring data and pre-processing to modality specific data procedures. Until now, no single toolbox was able to perform such investigations on truly multimodal image data from beginning to end, including the combination of different connectivity analyses. Thus, we have developed the Multimodal Imaging Brain Connectivity Analysis (MIBCA toolbox with the goal of diminishing time waste in data processing and to allow an innovative and comprehensive approach to brain connectivity.Materials and Methods. The MIBCA toolbox is a fully automated all-in-one connectivity toolbox that offers pre-processing, connectivity and graph theoretical analyses of multimodal image data such as diffusion-weighted imaging, functional magnetic resonance imaging (fMRI and positron emission tomography (PET. It was developed in MATLAB environment and pipelines well-known neuroimaging softwares such as Freesurfer, SPM, FSL, and Diffusion Toolkit. It further implements routines for the construction of structural, functional and effective or combined connectivity matrices, as well as, routines for the extraction and calculation of imaging and graph-theory metrics, the latter using also functions from the Brain Connectivity Toolbox. Finally, the toolbox performs group statistical analysis and enables data visualization in the form of matrices, 3D brain graphs and connectograms. In this paper the MIBCA toolbox is presented by illustrating its capabilities using multimodal image data from a group of 35 healthy subjects (19–73 years old with volumetric T1-weighted, diffusion tensor imaging, and resting state fMRI data, and 10 subjets with 18F-Altanserin PET data also.Results. It was observed both a high inter

  7. Biomedical applications of photoacoustic imaging with exogenous contrast agents.

    Science.gov (United States)

    Luke, Geoffrey P; Yeager, Doug; Emelianov, Stanislav Y

    2012-02-01

    Photoacoustic imaging is a biomedical imaging modality that provides functional information, and, with the help of exogenous contrast agents, cellular and molecular signatures of tissue. In this article, we review the biomedical applications of photoacoustic imaging assisted with exogenous contrast agents. Dyes, noble metal nanoparticles, and other constructs are contrast agents which absorb strongly in the near-infrared band of the optical spectrum and generate strong photoacoustic response. These contrast agents, which can be specifically targeted to molecules or cells, have been coupled with photoacoustic imaging for preclinical and clinical applications ranging from detection of cancer cells, sentinel lymph nodes, and micrometastasis to angiogenesis to characterization of atherosclerotic plaques. Multi-functional agents have also been developed, which can carry drugs or simultaneously provide contrast in multiple imaging modalities. Furthermore, contrast agents were used to guide and monitor the therapeutic procedures. Overall, photoacoustic imaging shows significant promise in its ability to assist in diagnosis, therapy planning, and monitoring of treatment outcome for cancer, cardiovascular disease, and other pathologies.

  8. Magnetic resonance imaging of the fetal brain.

    Science.gov (United States)

    Tee, L Mf; Kan, E Yl; Cheung, J Cy; Leung, W C

    2016-06-01

    This review covers the recent literature on fetal brain magnetic resonance imaging, with emphasis on techniques, advances, common indications, and safety. We conducted a search of MEDLINE for articles published after 2010. The search terms used were "(fetal OR foetal OR fetus OR foetus) AND (MR OR MRI OR [magnetic resonance]) AND (brain OR cerebral)". Consensus statements from major authorities were also included. As a result, 44 relevant articles were included and formed the basis of this review. One major challenge is fetal motion that is largely overcome by ultra-fast sequences. Currently, single-shot fast spin-echo T2-weighted imaging remains the mainstay for motion resistance and anatomical delineation. Recently, a snap-shot inversion recovery sequence has enabled robust T1-weighted images to be obtained, which is previously a challenge for standard gradient-echo acquisitions. Fetal diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy are also being developed. With multiplanar capabilities, superior contrast resolution and field of view, magnetic resonance imaging does not have the limitations of sonography, and can provide additional important information. Common indications include ventriculomegaly, callosum and posterior fossa abnormalities, and twin complications. There are safety concerns about magnetic resonance-induced heating and acoustic damage but current literature showed no conclusive evidence of deleterious fetal effects. The American College of Radiology guideline states that pregnant patients can be accepted to undergo magnetic resonance imaging at any stage of pregnancy if risk-benefit ratio to patients warrants that the study be performed. Magnetic resonance imaging of the fetal brain is a safe and powerful adjunct to sonography in prenatal diagnosis. It can provide additional information that aids clinical management, prognostication, and counselling.

  9. Semiautomatic brain morphometry from CT images

    Science.gov (United States)

    Soltanian-Zadeh, Hamid; Windham, Joe P.; Peck, Donald J.

    1994-05-01

    Fast, accurate, and reproducible volume estimation is vital to the diagnosis, treatment, and evaluation of many medical situations. We present the development and application of a semi-automatic method for estimating volumes of normal and abnormal brain tissues from computed tomography images. This method does not require manual drawing of the tissue boundaries. It is therefore expected to be faster and more reproducible than conventional methods. The steps of the new method are as follows. (1) The intracranial brain volume is segmented from the skull and background using thresholding and morphological operations. (2) The additive noise is suppressed (the image is restored) using a non-linear edge-preserving filter which preserves partial volume information on average. (3) The histogram of the resulting low-noise image is generated and the dominant peak is removed from it using a Gaussian model. (4) Minima and maxima of the resulting histogram are identified and using a minimum error criterion, the brain is segmented into the normal tissues (white matter and gray matter), cerebrospinal fluid, and lesions, if present. (5) Previous steps are repeated for each slice through the brain and the volume of each tissue type is estimated from the results. Details and significance of each step are explained. Experimental results using a simulation, a phantom, and selected clinical cases are presented.

  10. Visceral Afferent Pathways and Functional Brain Imaging

    Directory of Open Access Journals (Sweden)

    Stuart W.G. Derbyshire

    2003-01-01

    Full Text Available The application of functional imaging to study painful sensations has generated considerable interest regarding insight into brain dysfunction that may be responsible for functional pain such as that suffered in patients with irritable bowel syndrome (IBS. This review provides a brief introduction to the development of brain science as it relates to pain processing and a snapshot of recent functional imaging results with somatic and visceral pain. Particular emphasis is placed on current hypotheses regarding dysfunction of the brain-gut axis in IBS patients. There are clear and interpretable differences in brain activation following somatic as compared with visceral noxious sensation. Noxious visceral distension, particularly of the lower gastrointestinal tract, activates regions associated with unpleasant affect and autonomic responses. Noxious somatic sensation, in contrast, activates regions associated with cognition and skeletomotor responses. Differences between IBS patients and control subjects, however, were far less clear and interpretable. While this is in part due to the newness of this field, it also reflects weaknesses inherent within the current understanding of IBS. Future use of functional imaging to examine IBS and other functional disorders will be more likely to succeed by describing clear theoretical and clinical endpoints.

  11. Phase imaging in brain using SWIFT

    Science.gov (United States)

    Lehto, Lauri Juhani; Garwood, Michael; Gröhn, Olli; Corum, Curtis Andrew

    2015-03-01

    The majority of MRI phase imaging is based on gradient recalled echo (GRE) sequences. This work studies phase contrast behavior due to small off-resonance frequency offsets in brain using SWIFT, a FID-based sequence with nearly zero acquisition delay. 1D simulations and a phantom study were conducted to describe the behavior of phase accumulation in SWIFT. Imaging experiments of known brain phase contrast properties were conducted in a perfused rat brain comparing GRE and SWIFT. Additionally, a human brain sample was imaged. It is demonstrated how SWIFT phase is orientation dependent and correlates well with GRE, linking SWIFT phase to similar off-resonance sources as GRE. The acquisition time is shown to be analogous to TE for phase accumulation time. Using experiments with and without a magnetization transfer preparation, the likely effect of myelin water pool contribution is seen as a phase increase for all acquisition times. Due to the phase accumulation during acquisition, SWIFT phase contrast can be sensitized to small frequency differences between white and gray matter using low acquisition bandwidths.

  12. Electromagnetic imaging of dynamic brain activity

    Energy Technology Data Exchange (ETDEWEB)

    Mosher, J.; Leahy, R. [University of Southern California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Lewis, P.; Lewine, J.; George, J. [Los Alamos National Lab., NM (United States); Singh, M. [University of Southern California, Los Angeles, CA (United States). Dept. of Radiology

    1991-12-31

    Neural activity in the brain produces weak dynamic electromagnetic fields that can be measured by an array of sensors. Using a spatio-temporal modeling framework, we have developed a new approach to localization of multiple neural sources. This approach is based on the MUSIC algorithm originally developed for estimating the direction of arrival of signals impinging on a sensor array. We present applications of this technique to magnetic field measurements of a phantom and of a human evoked somatosensory response. The results of the somatosensory localization are mapped onto the brain anatomy obtained from magnetic resonance images.

  13. A dedicated neonatal brain imaging system

    Science.gov (United States)

    Winchman, Tobias; Padormo, Francesco; Teixeira, Rui; Wurie, Julia; Sharma, Maryanne; Fox, Matthew; Hutter, Jana; Cordero‐Grande, Lucilio; Price, Anthony N.; Allsop, Joanna; Bueno‐Conde, Jose; Tusor, Nora; Arichi, Tomoki; Edwards, A. D.; Rutherford, Mary A.; Counsell, Serena J.; Hajnal, Joseph V.

    2016-01-01

    Purpose The goal of the Developing Human Connectome Project is to acquire MRI in 1000 neonates to create a dynamic map of human brain connectivity during early development. High‐quality imaging in this cohort without sedation presents a number of technical and practical challenges. Methods We designed a neonatal brain imaging system (NBIS) consisting of a dedicated 32‐channel receive array coil and a positioning device that allows placement of the infant's head deep into the coil for maximum signal‐to‐noise ratio (SNR). Disturbance to the infant was minimized by using an MRI‐compatible trolley to prepare and transport the infant and by employing a slow ramp‐up and continuation of gradient noise during scanning. Scan repeats were minimized by using a restart capability for diffusion MRI and retrospective motion correction. We measured the 1) SNR gain, 2) number of infants with a completed scan protocol, and 3) number of anatomical images with no motion artifact using NBIS compared with using an adult 32‐channel head coil. Results The NBIS has 2.4 times the SNR of the adult coil and 90% protocol completion rate. Conclusion The NBIS allows advanced neonatal brain imaging techniques to be employed in neonatal brain imaging with high protocol completion rates. Magn Reson Med 78:794–804, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. PMID:27643791

  14. A dedicated neonatal brain imaging system.

    Science.gov (United States)

    Hughes, Emer J; Winchman, Tobias; Padormo, Francesco; Teixeira, Rui; Wurie, Julia; Sharma, Maryanne; Fox, Matthew; Hutter, Jana; Cordero-Grande, Lucilio; Price, Anthony N; Allsop, Joanna; Bueno-Conde, Jose; Tusor, Nora; Arichi, Tomoki; Edwards, A D; Rutherford, Mary A; Counsell, Serena J; Hajnal, Joseph V

    2017-08-01

    The goal of the Developing Human Connectome Project is to acquire MRI in 1000 neonates to create a dynamic map of human brain connectivity during early development. High-quality imaging in this cohort without sedation presents a number of technical and practical challenges. We designed a neonatal brain imaging system (NBIS) consisting of a dedicated 32-channel receive array coil and a positioning device that allows placement of the infant's head deep into the coil for maximum signal-to-noise ratio (SNR). Disturbance to the infant was minimized by using an MRI-compatible trolley to prepare and transport the infant and by employing a slow ramp-up and continuation of gradient noise during scanning. Scan repeats were minimized by using a restart capability for diffusion MRI and retrospective motion correction. We measured the 1) SNR gain, 2) number of infants with a completed scan protocol, and 3) number of anatomical images with no motion artifact using NBIS compared with using an adult 32-channel head coil. The NBIS has 2.4 times the SNR of the adult coil and 90% protocol completion rate. The NBIS allows advanced neonatal brain imaging techniques to be employed in neonatal brain imaging with high protocol completion rates. Magn Reson Med 78:794-804, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  15. Advanced Contrast Agents for Multimodal Biomedical Imaging Based on Nanotechnology.

    Science.gov (United States)

    Calle, Daniel; Ballesteros, Paloma; Cerdán, Sebastián

    2018-01-01

    Clinical imaging modalities have reached a prominent role in medical diagnosis and patient management in the last decades. Different image methodologies as Positron Emission Tomography, Single Photon Emission Tomography, X-Rays, or Magnetic Resonance Imaging are in continuous evolution to satisfy the increasing demands of current medical diagnosis. Progress in these methodologies has been favored by the parallel development of increasingly more powerful contrast agents. These are molecules that enhance the intrinsic contrast of the images in the tissues where they accumulate, revealing noninvasively the presence of characteristic molecular targets or differential physiopathological microenvironments. The contrast agent field is currently moving to improve the performance of these molecules by incorporating the advantages that modern nanotechnology offers. These include, mainly, the possibilities to combine imaging and therapeutic capabilities over the same theranostic platform or improve the targeting efficiency in vivo by molecular engineering of the nanostructures. In this review, we provide an introduction to multimodal imaging methods in biomedicine, the sub-nanometric imaging agents previously used and the development of advanced multimodal and theranostic imaging agents based in nanotechnology. We conclude providing some illustrative examples from our own laboratories, including recent progress in theranostic formulations of magnetoliposomes containing ω-3 poly-unsaturated fatty acids to treat inflammatory diseases, or the use of stealth liposomes engineered with a pH-sensitive nanovalve to release their cargo specifically in the acidic extracellular pH microenvironment of tumors.

  16. 64Cu loaded liposomes as positron emission tomography imaging agents

    DEFF Research Database (Denmark)

    Petersen, Anncatrine Luisa; Binderup, Tina; Rasmussen, Palle

    2011-01-01

    We have developed a highly efficient method for utilizing liposomes as imaging agents for positron emission tomography (PET) giving high resolution images and allowing direct quantification of tissue distribution and blood clearance. Our approach is based on remote loading of a copper-radionuclid...

  17. Introduction to machine learning for brain imaging.

    Science.gov (United States)

    Lemm, Steven; Blankertz, Benjamin; Dickhaus, Thorsten; Müller, Klaus-Robert

    2011-05-15

    Machine learning and pattern recognition algorithms have in the past years developed to become a working horse in brain imaging and the computational neurosciences, as they are instrumental for mining vast amounts of neural data of ever increasing measurement precision and detecting minuscule signals from an overwhelming noise floor. They provide the means to decode and characterize task relevant brain states and to distinguish them from non-informative brain signals. While undoubtedly this machinery has helped to gain novel biological insights, it also holds the danger of potential unintentional abuse. Ideally machine learning techniques should be usable for any non-expert, however, unfortunately they are typically not. Overfitting and other pitfalls may occur and lead to spurious and nonsensical interpretation. The goal of this review is therefore to provide an accessible and clear introduction to the strengths and also the inherent dangers of machine learning usage in the neurosciences. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Magnetic resonance imaging in diffuse brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, Hiroyuki; Yasuda, Kazuhiro; Mashiko, Kunihiro; Henmi, Hiroshi; Otsuka, Toshibumi; Kobayashi, Shiro; Nakazawa, Shozo (Nippon Medical School, Tokyo (Japan))

    1992-01-01

    Forty cases diagnosed as diffuse brain injury (DBI) were studied by magnetic resonance imaging (MRI) performed within 3 days after injury. These cases were divided into two groups, which were the concussion group and diffuse axonal injury (DAI) group established by Gennarelli. There were no findings on computerized tomography (CT) in the concussion group except for two cases which had a brain edema or subarachnoid hemorrhage. But on MRI, high intensity areas on T2 weighted imaging were demonstrated in the cerebral white matter in this group. Many lesions in this group were thought to be edemas of the cerebral white matter, because of the fact that on serial MRI, they were isointense. In mild types of DAI, the lesions on MRI were located only in the cerebral white matter, whereas, in the severe types of DAI, lesions were located in the basal ganglia, the corpus callosum, the dorsal part of the brain stem as well as in the cerebral white matter. As for CT findings, parenchymal lesions were not visualized especially in mild DAI. Our results suggested that the lesions in cerebral concussion were edemas in cerebral white matter. In mild DAI they were non-hemorrhagic contusion; and in severe DAI they were hemorrhagic contusions in the cerebral white matter, the basal ganglia, the corpus callosum or the dorsal part of the brain stem. (author).

  19. Multifunctional Photosensitizer-Based Contrast Agents for Photoacoustic Imaging

    Science.gov (United States)

    Ho, Chris Jun Hui; Balasundaram, Ghayathri; Driessen, Wouter; McLaren, Ross; Wong, Chi Lok; Dinish, U. S.; Attia, Amalina Binte Ebrahim; Ntziachristos, Vasilis; Olivo, Malini

    2014-06-01

    Photoacoustic imaging is a novel hybrid imaging modality combining the high spatial resolution of optical imaging with the high penetration depth of ultrasound imaging. Here, for the first time, we evaluate the efficacy of various photosensitizers that are widely used as photodynamic therapeutic (PDT) agents as photoacoustic contrast agents. Photoacoustic imaging of photosensitizers exhibits advantages over fluorescence imaging, which is prone to photobleaching and autofluorescence interference. In this work, we examined the photoacoustic activity of 5 photosensitizers: zinc phthalocyanine, protoporphyrin IX, 2,4-bis [4-(N,N-dibenzylamino)-2,6-dihydroxyphenyl] squaraine, chlorin e6 and methylene blue in phantoms, among which zinc phthalocyanine showed the highest photoacoustic activity. Subsequently, we evaluated its tumor localization efficiency and biodistribution at multiple time points in a murine model using photoacoustic imaging. We observed that the probe localized at the tumor within 10 minutes post injection, reaching peak accumulation around 1 hour and was cleared within 24 hours, thus, demonstrating the potential of photosensitizers as photoacoustic imaging contrast agents in vivo. This means that the known advantages of photosensitizers such as preferential tumor uptake and PDT efficacy can be combined with photoacoustic imaging capabilities to achieve longitudinal monitoring of cancer progression and therapy in vivo.

  20. [Brain imaging of first-episode psychosis].

    Science.gov (United States)

    Jardri, R

    2013-09-01

    In the last decades, schizophrenia has intensively been studied using various brain imaging techniques. However, several potential confounding factors limited their interpretation power (e.g. chronicity, the impact of antipsychotic medication). By considering psychosis as a continuum of changes starting from mild cognitive impairments to serious psychotic symptoms, it became possible to provide deeper insight in the neurobiological mechanisms underlying the onset of psychosis by focusing on at-risk individuals and first-episodes. Recent brain imaging meta-analyses of the first episode psychosis (FEP), noteworthy reported conjoint bilateral structural and functional differences at the level of the insula, the superior temporal gyrus and the medial frontal gyrus, encompassing the anterior cingulate cortex. In the present review, we thus provide an update of brain imaging studies of FEP with a particular emphasis on more recent anatomical, functional and molecular explorations. Specifically, we provide 1) a review of the common features observed in individuals with high risk for psychosis and changes characterizing the transition to psychosis, 2) a description of the environmental and drug factors influencing these abnormalities, 3) how these findings in FEP may differ from those observed in chronic individuals with schizophrenia, and 4) a short overview of new classification algorithms able to use MRI findings as valuable biomarkers to guide early detection in the prodromal phase of psychosis. Copyright © 2013 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

  1. FCM Clustering Algorithms for Segmentation of Brain MR Images

    OpenAIRE

    Yogita K. Dubey; Mushrif, Milind M.

    2016-01-01

    The study of brain disorders requires accurate tissue segmentation of magnetic resonance (MR) brain images which is very important for detecting tumors, edema, and necrotic tissues. Segmentation of brain images, especially into three main tissue types: Cerebrospinal Fluid (CSF), Gray Matter (GM), and White Matter (WM), has important role in computer aided neurosurgery and diagnosis. Brain images mostly contain noise, intensity inhomogeneity, and weak boundaries. Therefore, accurate segmentati...

  2. Silicon nanoparticles as hyperpolarized magnetic resonance imaging agents.

    Science.gov (United States)

    Aptekar, Jacob W; Cassidy, Maja C; Johnson, Alexander C; Barton, Robert A; Lee, Menyoung; Ogier, Alexander C; Vo, Chinh; Anahtar, Melis N; Ren, Yin; Bhatia, Sangeeta N; Ramanathan, Chandrasekhar; Cory, David G; Hill, Alison L; Mair, Ross W; Rosen, Matthew S; Walsworth, Ronald L; Marcus, Charles M

    2009-12-22

    Magnetic resonance imaging of hyperpolarized nuclei provides high image contrast with little or no background signal. To date, in vivo applications of prehyperpolarized materials have been limited by relatively short nuclear spin relaxation times. Here, we investigate silicon nanoparticles as a new type of hyperpolarized magnetic resonance imaging agent. Nuclear spin relaxation times for a variety of Si nanoparticles are found to be remarkably long, ranging from many minutes to hours at room temperature, allowing hyperpolarized nanoparticles to be transported, administered, and imaged on practical time scales. Additionally, we demonstrate that Si nanoparticles can be surface functionalized using techniques common to other biologically targeted nanoparticle systems. These results suggest that Si nanoparticles can be used as a targetable, hyperpolarized magnetic resonance imaging agent with a large range of potential applications.

  3. Recent Advances in Higher-Order, Multimodal, Biomedical Imaging Agents.

    Science.gov (United States)

    Rieffel, James; Chitgupi, Upendra; Lovell, Jonathan F

    2015-09-16

    Advances in biomedical imaging have spurred the development of integrated multimodal scanners, usually capable of two simultaneous imaging modes. The long-term vision of higher-order multimodality is to improve diagnostics or guidance through the analysis of complementary, data-rich, co-registered images. Synergies achieved through combined modalities could enable researchers to better track diverse physiological and structural events, analyze biodistribution and treatment efficacy, and compare established and emerging modalities. Higher-order multimodal approaches stand to benefit from molecular imaging probes and, in recent years, contrast agents that have hypermodal characteristics have increasingly been reported in preclinical studies. Given the chemical requirements for contrast agents representing various modalities to be integrated into a single entity, the higher-order multimodal agents reported so far tend to be of nanoparticulate form. To date, the majority of reported nanoparticles have included components that are active for magnetic resonance. Herein, recent progress in higher-order multimodal imaging agents is reviewed, spanning a range of material and structural classes, and demonstrating utility in three (or more) imaging modalities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Gadolinium-based contrast agents in pediatric magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gale, Eric M.; Caravan, Peter [Massachusetts General Hospital, Harvard Medical School, Department of Radiology, The Martinos Center for Biomedical Imaging, Boston, MA (United States); Rao, Anil G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); McDonald, Robert J. [College of Medicine, Mayo Clinic, Department of Radiology, Rochester, MN (United States); Winfeld, Matthew [University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Pediatric Radiology, Cincinnati, OH (United States); Gee, Michael S. [MassGeneral Hospital for Children, Harvard Medical School, Division of Pediatric Imaging, Department of Radiology, Boston, MA (United States)

    2017-05-15

    Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available. (orig.)

  5. {sup 18}F-labeled styrylpyridines as PET agents for amyloid plaque imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wei [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kung Meip ing [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Oya, Shunichi [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Hou, Catherine [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kung, Hank F. [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States)]. E-mail: kunghf@sunmac.spect.upenn.edu

    2007-01-15

    Positron emission tomography (PET) imaging of {beta}-amyloid (A{beta}) plaques in the brain is a potentially valuable tool for studying the pathophysiology of Alzheimer's disease (AD). It may also be applicable for measuring the effectiveness of therapeutic drugs aimed at lowering A{beta} plaques in the brain. We have successfully reported a series of {sup 18}F-labeled fluoropegylated stilbenes for PET imaging studies. Encouraging results clearly demonstrated the usefulness of {sup 18}F-labeled stilbenes as potential A{beta} plaque-imaging agents. In the present study, we applied a similar approach to a styrylpyridine backbone structure. Among all derivatives examined (E)-2-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)-5-(4-dimethylaminostyryl) -pyridine (2) displayed high binding affinity in postmortem AD brain homogenates (K {sub i}=2.5{+-}0.4 nM, with [{sup 125}I]IMPY as radioligand). No-carrier-added [{sup 18}F]2 was successfully prepared by [{sup 18}F]fluoride displacement of the corresponding tosylate precursor with a high labeling yield (30-40%) and a high radiochemical purity (>99%). Specific activity at the end of synthesis was determined to be 1500-2000 Ci/mmol. The tracer [{sup 18}F]2 showed adequate lipophilicity (log P=3.22). In vivo biodistribution of [{sup 18}F]2 in normal mice exhibited excellent initial brain penetration and rapid washout (7.77% and 1.03% dose/g in the brain at 2 and 30 min after intravenous injection, respectively) - properties that are highly desirable for A{beta}-plaque-specific brain imaging agents. Autoradiography of AD brain sections and homogenate binding with postmortem AD brain tissues confirmed the high binding signal of [{sup 18}F]2 due to the presence of A{beta} plaques. These preliminary results suggest that novel PET tracers may be potentially useful for the imaging of A{beta} plaques in the living human brain.

  6. Diffuse Optical Tomography for Brain Imaging: Theory

    Science.gov (United States)

    Yuan, Zhen; Jiang, Huabei

    Diffuse optical tomography (DOT) is a noninvasive, nonionizing, and inexpensive imaging technique that uses near-infrared light to probe tissue optical properties. Regional variations in oxy- and deoxy-hemoglobin concentrations as well as blood flow and oxygen consumption can be imaged by monitoring spatiotemporal variations in the absorption spectra. For brain imaging, this provides DOT unique abilities to directly measure the hemodynamic, metabolic, and neuronal responses to cells (neurons), and tissue and organ activations with high temporal resolution and good tissue penetration. DOT can be used as a stand-alone modality or can be integrated with other imaging modalities such as fMRI/MRI, PET/CT, and EEG/MEG in studying neurophysiology and pathology. This book chapter serves as an introduction to the basic theory and principles of DOT for neuroimaging. It covers the major aspects of advances in neural optical imaging including mathematics, physics, chemistry, reconstruction algorithm, instrumentation, image-guided spectroscopy, neurovascular and neurometabolic coupling, and clinical applications.

  7. Dendrimer-entrapped metal colloids as imaging agents.

    Science.gov (United States)

    Li, Du; Wen, Shihui; Shi, Xiangyang

    2015-01-01

    This review reports the recent advances in dendrimer-entrapped metal colloids as contrast agents for biomedical imaging applications. The versatile dendrimer scaffolds with 3-dimensional spherical shape, highly branched internal cavity, tunable surface conjugation chemistry, and excellent biocompatibility and nonimmunogenicity afford their uses as templates to create multifunctional dendrimer-entrapped metal colloids for mono- or multi- mode molecular imaging applications. In particular, multifunctional dendrimer-entrapped gold nanoparticles with different surface modifications have been used for fluorescence imaging, targeted tumor computed tomography (CT) imaging, enhanced blood pool CT imaging, dual mode CT/MR imaging, and tumor theranostics (combined CT imaging and chemotherapy) will be introduced and discussed in detail. © 2015 Wiley Periodicals, Inc.

  8. Role of Hybrid Brain Imaging in Neuropsychiatric Disorders.

    Science.gov (United States)

    Burhan, Amer M; Marlatt, Nicole M; Palaniyappan, Lena; Anazodo, Udunna C; Prato, Frank S

    2015-12-04

    This is a focused review of imaging literature to scope the utility of hybrid brain imaging in neuropsychiatric disorders. The review focuses on brain imaging modalities that utilize hybrid (fusion) techniques to characterize abnormal brain molecular signals in combination with structural and functional changes that have been observed in neuropsychiatric disorders. An overview of clinical hybrid brain imaging technologies for human use is followed by a selective review of the literature that conceptualizes the use of these technologies in understanding basic mechanisms of major neuropsychiatric disorders and their therapeutics. Neuronal network abnormalities are highlighted throughout this review to scope the utility of hybrid imaging as a potential biomarker for each disorder.

  9. Metal-organic frameworks as sensory materials and imaging agents.

    Science.gov (United States)

    Liu, Demin; Lu, Kuangda; Poon, Christopher; Lin, Wenbin

    2014-02-17

    Metal-organic frameworks (MOFs) are a class of hybrid materials self-assembled from organic bridging ligands and metal ion/cluster connecting points. The combination of a variety of organic linkers, metal ions/clusters, and structural motifs can lead to an infinite array of new materials with interesting properties for many applications. In this Forum Article, we discuss the design and applications of MOFs in chemical sensing and biological imaging. The first half of this article focuses on the development of MOFs as chemical sensors by highlighting how unique attributes of MOFs can be utilized to enhance sensitivity and selectivity. We also discuss some of the issues that need to be addressed in order to develop practically useful MOF sensors. The second half of this article focuses on the design and applications of nanoscale MOFs (NMOFs) as imaging contrast agents. NMOFs possess several interesting attributes, such as high cargo loading capacity, ease of postmodification, tunable size and shape, and intrinsic biodegradability, to make them excellent candidates as imaging contrast agents. We discuss the use of representative NMOFs in magnetic resonance imaging (MRI), X-ray computed tomography (CT), and optical imaging. Although still in their infancy, we believe that the compositional tunability and mild synthetic conditions of NMOF imaging agents should greatly facilitate their further development for clinical translation.

  10. Contrast-agent-enhanced magnetic resonance imaging: early detection of neoplastic lesions of the CNS

    Science.gov (United States)

    Carvlin, Mark J.; Rosa, Louis; Rajan, Sunder S.; Francisco, John

    1991-06-01

    Even though the intrinsic soft tissue contrast sensitivity of magnetic resonance imaging (MRI) affords excellent visualization of anatomic detail, certain pathologic processes may be diagnosed earlier with the administration of a contrast-enhancing agent. At present there is one agent, gadopentetate dimeglumine, GdDTPA, that has received FDA approval for use in the MR scanning of the brain and spine in human patients. This paramagnetic chelate distributes throughout the extracellular fluid space as dictated by capillary permeability so that abnormal vascularity and sites of blood-CNS barrier breakdown are highlighted. Primary neoplastic disease, metastases, meningeal extension, residual and recurrent tumor have been found to be better distinguished in MR images acquired after administration of GdDTPA. Routine administration of GdDTPA for cranial imaging has resulted in the discovery of otherwise occult lesions in approximately 3 of patients. Although the clinical utility and high therapeutic safety index of the first approved magnetic resonance contrast agent, GdDTPA, have been well established, other contrast agents, having different physical, chemical and biological properties, may offer improved sensitivity and bio-specificity. Agents currently being evaluated in vivo include: low osmolal paramagnetic chelates, superparamagnetic particles, metalloporphyrins, liposome encapsulated agents, perfluorocarbons, intravascular macromolecular chelate complexes and labeled monoclonal antibodies. Concurrent with advances in the development of new compounds, innovations in scanning hardware, pulse sequence design and image post-processing are helping to extend the efficacy of contrast media. Additional clinical experience will indicate which contrast agents and which MR techniques can best facilitate the early detection of specific neoplastic lesions.

  11. Electric and magnetic properties of contrast agents for thermoacoustic imaging

    Science.gov (United States)

    Ogunlade, Olumide; Beard, Paul

    2014-03-01

    The endogenous contrast in thermoacoustic imaging is due to the water and ionic content in tissue. This results in poor tissue speci city between high water content tissues. As a result, exogenous contrast agents have been employed to improve tissue speci city and also increase the SNR. An investigation into the sources of contrast produced by several exogenous contrast agents is described. These include three gadolinium based MRI contrast agents, iron oxide particles, single wall carbon nanotubes, saline and sucrose solutions. Both the dielectric and magnetic properties of contrast agents at 3GHz have been measured using microwave resonant cavities. The DC conductivity of the contrast agents were also measured. It is shown that the measured increase in dielectric contrast, relative to water, is due to dipole rotational loss of polar non electrolytes, ionic loss of electrolytes or a combination of both. It is shown that for the same dielectric contrast, electrolytes make better thermoacoustic contrast agents than non-electrolytes, for thermoacoustic imaging.

  12. Susceptibility weighted imaging of the neonatal brain

    Energy Technology Data Exchange (ETDEWEB)

    Meoded, A.; Poretti, A. [Division of Pediatric Radiology and Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Northington, F.J. [Division of Neonatology, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tekes, A.; Intrapiromkul, J. [Division of Pediatric Radiology and Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Huisman, T.A.G.M., E-mail: thuisma1@jhmi.edu [Division of Pediatric Radiology and Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD (United States)

    2012-08-15

    Susceptibility weighted imaging (SWI) is a well-established magnetic resonance technique, which is highly sensitive for blood, iron, and calcium depositions in the brain and has been implemented in the routine clinical use in both children and neonates. SWI in neonates might provide valuable additional diagnostic and prognostic information for a wide spectrum of neonatal neurological disorders. To date, there are few articles available on the application of SWI in neonatal neurological disorders. The purpose of this article is to illustrate and describe the characteristic SWI findings in various typical neonatal neurological disorders.

  13. Dynamic fluorescence imaging with molecular agents for cancer detection

    Science.gov (United States)

    Kwon, Sun Kuk

    Non-invasive dynamic optical imaging of small animals requires the development of a novel fluorescence imaging modality. Herein, fluorescence imaging is demonstrated with sub-second camera integration times using agents specifically targeted to disease markers, enabling rapid detection of cancerous regions. The continuous-wave fluorescence imaging acquires data with an intensified or an electron-multiplying charge-coupled device. The work presented in this dissertation (i) assessed dose-dependent uptake using dynamic fluorescence imaging and pharmacokinetic (PK) models, (ii) evaluated disease marker availability in two different xenograft tumors, (iii) compared the impact of autofluorescence in fluorescence imaging of near-infrared (NIR) vs. red light excitable fluorescent contrast agents, (iv) demonstrated dual-wavelength fluorescence imaging of angiogenic vessels and lymphatics associated with a xenograft tumor model, and (v) examined dynamic multi-wavelength, whole-body fluorescence imaging with two different fluorescent contrast agents. PK analysis showed that the uptake of Cy5.5-c(KRGDf) in xenograft tumor regions linearly increased with doses of Cy5.5-c(KRGDf) up to 1.5 nmol/mouse. Above 1.5 nmol/mouse, the uptake did not increase with doses, suggesting receptor saturation. Target to background ratio (TBR) and PK analysis for two different tumor cell lines showed that while Kaposi's sarcoma (KS1767) exhibited early and rapid uptake of Cy5.5-c(KRGDf), human melanoma tumors (M21) had non-significant TBR differences and early uptake rates similar to the contralateral normal tissue regions. The differences may be due to different compartment location of the target. A comparison of fluorescence imaging with NIR vs. red light excitable fluorescent dyes demonstrates that NIR dyes are associated with less background signal, enabling rapid tumor detection. In contrast, animals injected with red light excitable fluorescent dyes showed high autofluorescence. Dual

  14. Brain Extraction from Normal and Pathological Images: A Joint PCA/Image-Reconstruction Approach

    OpenAIRE

    Han, Xu; Kwitt, Roland; Aylward, Stephen; Menze, Bjoern; Asturias, Alexander; Vespa, Paul; Horn, John; Niethammer, Marc

    2017-01-01

    Brain extraction from 3D medical images is a common pre-processing step. A variety of approaches exist, but they are frequently only designed to perform brain extraction from images without strong pathologies. Extracting the brain from images exhibiting strong pathologies, for example, the presence of a brain tumor or of a traumatic brain injury (TBI), is challenging. In such cases, tissue appearance may deviate from normal tissue appearance and hence violates algorithmic assumptions for stan...

  15. Ultrasound imaging beyond the vasculature with new generation contrast agents.

    Science.gov (United States)

    Perera, Reshani H; Hernandez, Christopher; Zhou, Haoyan; Kota, Pavan; Burke, Alan; Exner, Agata A

    2015-01-01

    Current commercially available ultrasound contrast agents are gas-filled, lipid- or protein-stabilized microbubbles larger than 1 µm in diameter. Because the signal generated by these agents is highly dependent on their size, small yet highly echogenic particles have been historically difficult to produce. This has limited the molecular imaging applications of ultrasound to the blood pool. In the area of cancer imaging, microbubble applications have been constrained to imaging molecular signatures of tumor vasculature and drug delivery enabled by ultrasound-modulated bubble destruction. Recently, with the rise of sophisticated advancements in nanomedicine, ultrasound contrast agents, which are an order of magnitude smaller (100-500 nm) than their currently utilized counterparts, have been undergoing rapid development. These agents are poised to greatly expand the capabilities of ultrasound in the field of targeted cancer detection and therapy by taking advantage of the enhanced permeability and retention phenomenon of many tumors and can extravasate beyond the leaky tumor vasculature. Agent extravasation facilitates highly sensitive detection of cell surface or microenvironment biomarkers, which could advance early cancer detection. Likewise, when combined with appropriate therapeutic agents and ultrasound-mediated deployment on demand, directly at the tumor site, these nanoparticles have been shown to contribute to improved therapeutic outcomes. Ultrasound's safety profile, broad accessibility and relatively low cost make it an ideal modality for the changing face of healthcare today. Aided by the multifaceted nano-sized contrast agents and targeted theranostic moieties described herein, ultrasound can considerably broaden its reach in future applications focused on the diagnosis and staging of cancer. © 2015 Wiley Periodicals, Inc.

  16. Image processing techniques for quantification and assessment of brain MRI

    NARCIS (Netherlands)

    Kuijf, H.J.

    2013-01-01

    Magnetic resonance imaging (MRI) is a widely used technique to acquire digital images of the human brain. A variety of acquisition protocols is available to generate images in vivo and noninvasively, giving great opportunities to study the anatomy and physiology of the human brain. In my thesis,

  17. Brain imaging and schizophrenia. Imagerie cerebrale et schizophrenie

    Energy Technology Data Exchange (ETDEWEB)

    Martinot, J.L. (Hopital de Bicetre, 94 - Le Kremlin-Bicetre (FR)); Dao-Castellana, M.H. (CEA, 91 - Orsay (FR). Service Hospitalier Frederic Joliot)

    1991-03-01

    Brain structures and brain function have been investigated by the new brain imaging techniques for more than ten years. In Psychiatry, these techniques could afford a new understanding of mental diseases. In schizophrenic patients, CAT scanner and RMI pointed out statistically significant ventricular enlargments which are presently considered as evidence for abnormalities in brain maturation. Functional imaging techniques reported metabolic dysfunctions in the cortical associative areas which are probably linked to the cognitive features of schizophrenics.

  18. De Novo Designed Imaging Agents Based on Lanthanide Peptides Complexes.

    Science.gov (United States)

    Peacock, A F A

    2016-01-01

    Herein are discussed a selection of lanthanide peptide/protein complexes in view of their potential applications as imaging agents, both in terms of luminescence detection and magnetic resonance imaging. Though this chapter covers a range of different peptides and protein, if focuses specifically on the opportunities afforded by the de novo design of coiled coils, miniature protein scaffolds, and the development on lanthanide-binding sites into these architectures. The requirements for lanthanide coordination and the challenges that need to be addressed when preparing lanthanide peptides with a view to their potential adoption as clinical imaging applications, will be highlighted. © 2016 Elsevier Inc. All rights reserved.

  19. Evaluation of the Efficacy of Targeted Imaging Agents

    Science.gov (United States)

    Graham, Michael M.; Weber, Wolfgang A.

    2016-01-01

    This paper presents our adaptation of Fryback and Thornbury’s hierarchical scheme for modeling the efficacy of diagnostic imaging systems. The original scheme was designed to evaluate new medical imaging systems but is less successful when applied to evaluate new radiopharmaceuticals. The proposed adaptation, which is specifically directed toward evaluating targeted imaging agents, has 6 levels: in vitro characterization, in vivo animal studies, initial human studies, impact on clinical care (change in management), impact on patient outcome, and societal efficacy. These levels, particularly the first four, implicitly define the sequence of studies needed to move an agent from the radiochemistry synthesis laboratory to the clinic. Completion of level 4 (impact on clinical care) should be sufficient for initial approval and reimbursement. We hope that the adapted scheme will help streamline the process and assist in bringing new targeted radiopharmaceuticals to approval over the next few years. PMID:26769867

  20. Sonophore labeled RGD: a targeted contrast agent for optoacoustic imaging

    Directory of Open Access Journals (Sweden)

    Katja Haedicke

    2017-06-01

    Full Text Available Optoacoustic imaging is a rapidly expanding field for the diagnosis, characterization, and treatment evaluation of cancer. However, the availability of tumor specific exogenous contrast agents is still limited. Here, we report on a small targeted contrast agent for optoacoustic imaging using a black hole quencher® (BHQ dye. The sonophore BHQ-1 exhibited strong, concentration-dependent, optoacoustic signals in phantoms, demonstrating its ideal suitability for optoacoustic imaging. After labeling BHQ-1 with cyclic RGD-peptide, BHQ-1-cRGD specifically bound to αvβ3-integrin expressing glioblastoma cell spheroids in vitro. The excellent optoacoustic properties of BHQ-1-cRGD could furthermore be proven in vivo. Together with this emerging imaging modality, our sonophore labeled small peptide probe offers new possibilities for non-invasive detection of molecular structures with high resolution in vivo and furthers the specificity of optoacoustic imaging. Ultimately, the discovery of tailor-made sonophores might offer new avenues for various molecular optoacoustic imaging applications, similar to what we see with fluorescence imaging.

  1. Sonophore labeled RGD: a targeted contrast agent for optoacoustic imaging.

    Science.gov (United States)

    Haedicke, Katja; Brand, Christian; Omar, Murad; Ntziachristos, Vasilis; Reiner, Thomas; Grimm, Jan

    2017-06-01

    Optoacoustic imaging is a rapidly expanding field for the diagnosis, characterization, and treatment evaluation of cancer. However, the availability of tumor specific exogenous contrast agents is still limited. Here, we report on a small targeted contrast agent for optoacoustic imaging using a black hole quencher ® (BHQ) dye. The sonophore BHQ-1 exhibited strong, concentration-dependent, optoacoustic signals in phantoms, demonstrating its ideal suitability for optoacoustic imaging. After labeling BHQ-1 with cyclic RGD-peptide, BHQ-1-cRGD specifically bound to α v β 3 -integrin expressing glioblastoma cell spheroids in vitro . The excellent optoacoustic properties of BHQ-1-cRGD could furthermore be proven in vivo . Together with this emerging imaging modality, our sonophore labeled small peptide probe offers new possibilities for non-invasive detection of molecular structures with high resolution in vivo and furthers the specificity of optoacoustic imaging. Ultimately, the discovery of tailor-made sonophores might offer new avenues for various molecular optoacoustic imaging applications, similar to what we see with fluorescence imaging.

  2. RNA aptamer probes as optical imaging agents for the detection of amyloid plaques.

    Directory of Open Access Journals (Sweden)

    Christian T Farrar

    Full Text Available Optical imaging using multiphoton microscopy and whole body near infrared imaging has become a routine part of biomedical research. However, optical imaging methods rely on the availability of either small molecule reporters or genetically encoded fluorescent proteins, which are challenging and time consuming to develop. While directly labeled antibodies can also be used as imaging agents, antibodies are species specific, can typically not be tagged with multiple fluorescent reporters without interfering with target binding, and are bioactive, almost always eliciting a biological response and thereby influencing the process that is being studied. We examined the possibility of developing highly specific and sensitive optical imaging agents using aptamer technology. We developed a fluorescently tagged anti-Aβ RNA aptamer, β55, which binds amyloid plaques in both ex vivo human Alzheimer's disease brain tissue and in vivo APP/PS1 transgenic mice. Diffuse β55 positive halos, attributed to oligomeric Aβ, were observed surrounding the methoxy-XO4 positive plaque cores. Dot blots of synthetic Aβ aggregates provide further evidence that β55 binds both fibrillar and non-fibrillar Aβ. The high binding affinity, the ease of probe development, and the ability to incorporate multiple and multimodal imaging reporters suggest that RNA aptamers may have complementary and perhaps advantageous properties compared to conventional optical imaging probes and reporters.

  3. Compact and mobile high resolution PET brain imager

    Science.gov (United States)

    Majewski, Stanislaw [Yorktown, VA; Proffitt, James [Newport News, VA

    2011-02-08

    A brain imager includes a compact ring-like static PET imager mounted in a helmet-like structure. When attached to a patient's head, the helmet-like brain imager maintains the relative head-to-imager geometry fixed through the whole imaging procedure. The brain imaging helmet contains radiation sensors and minimal front-end electronics. A flexible mechanical suspension/harness system supports the weight of the helmet thereby allowing for patient to have limited movements of the head during imaging scans. The compact ring-like PET imager enables very high resolution imaging of neurological brain functions, cancer, and effects of trauma using a rather simple mobile scanner with limited space needs for use and storage.

  4. Groupwise registration of MR brain images with tumors

    Science.gov (United States)

    Tang, Zhenyu; Wu, Yihong; Fan, Yong

    2017-09-01

    A novel groupwise image registration framework is developed for registering MR brain images with tumors. Our method iteratively estimates a normal-appearance counterpart for each tumor image to be registered and constructs a directed graph (digraph) of normal-appearance images to guide the groupwise image registration. Particularly, our method maps each tumor image to its normal appearance counterpart by identifying and inpainting brain tumor regions with intensity information estimated using a low-rank plus sparse matrix decomposition based image representation technique. The estimated normal-appearance images are groupwisely registered to a group center image guided by a digraph of images so that the total length of ‘image registration paths’ to be the minimum, and then the original tumor images are warped to the group center image using the resulting deformation fields. We have evaluated our method based on both simulated and real MR brain tumor images. The registration results were evaluated with overlap measures of corresponding brain regions and average entropy of image intensity information, and Wilcoxon signed rank tests were adopted to compare different methods with respect to their regional overlap measures. Compared with a groupwise image registration method that is applied to normal-appearance images estimated using the traditional low-rank plus sparse matrix decomposition based image inpainting, our method achieved higher image registration accuracy with statistical significance (p  =  7.02  ×  10-9).

  5. FCM Clustering Algorithms for Segmentation of Brain MR Images

    Directory of Open Access Journals (Sweden)

    Yogita K. Dubey

    2016-01-01

    Full Text Available The study of brain disorders requires accurate tissue segmentation of magnetic resonance (MR brain images which is very important for detecting tumors, edema, and necrotic tissues. Segmentation of brain images, especially into three main tissue types: Cerebrospinal Fluid (CSF, Gray Matter (GM, and White Matter (WM, has important role in computer aided neurosurgery and diagnosis. Brain images mostly contain noise, intensity inhomogeneity, and weak boundaries. Therefore, accurate segmentation of brain images is still a challenging area of research. This paper presents a review of fuzzy c-means (FCM clustering algorithms for the segmentation of brain MR images. The review covers the detailed analysis of FCM based algorithms with intensity inhomogeneity correction and noise robustness. Different methods for the modification of standard fuzzy objective function with updating of membership and cluster centroid are also discussed.

  6. Imaging retinotopic maps in the human brain

    Science.gov (United States)

    Wandell, Brian A.; Winawer, Jonathan

    2010-01-01

    A quarter-century ago visual neuroscientists had little information about the number and organization of retinotopic maps in human visual cortex. The advent of functional magnetic resonance imaging (MRI), a non-invasive, spatially-resolved technique for measuring brain activity, provided a wealth of data about human retinotopic maps. Just as there are differences amongst nonhuman primate maps, the human maps have their own unique properties. Many human maps can be measured reliably in individual subjects during experimental sessions lasting less than an hour. The efficiency of the measurements and the relatively large amplitude of functional MRI signals in visual cortex make it possible to develop quantitative models of functional responses within specific maps in individual subjects. During this last quarter century, there has also been significant progress in measuring properties of the human brain at a range of length and time scales, including white matter pathways, macroscopic properties of gray and white matter, and cellular and molecular tissue properties. We hope the next twenty-five years will see a great deal of work that aims to integrate these data by modeling the network of visual signals. We don’t know what such theories will look like, but the characterization of human retinotopic maps from the last twenty-five years is likely to be an important part of future ideas about visual computations. PMID:20692278

  7. Radiolabelled D2 agonists as prolactinoma imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Otto, C.A.

    1991-12-31

    Research conducted in this terminal year of support centered on three distinct areas: mAChR ligand localization in pancreas and the effect of Ca{sup +2} on localization, continuation of assessment of quaternized and neutral mAChR ligands for possible use as PET myocardial imaging agents, and initiation of a study to determine the relationship of the nAChR receptor to the cellular receptor for measles virus. Several tables and figures illustrating the results are included.

  8. Biocompatible astaxanthin as novel contrast agent for biomedical imaging.

    Science.gov (United States)

    Nguyen, Van Phuc; Park, Suhyun; Oh, Junghwan; Wook Kang, Hyun

    2017-08-01

    Photoacoustic imaging (PAI) is a hybrid imaging modality with high resolution and sensitivity that can be beneficial for cancer staging. Due to insufficient endogenous photoacoustic (PA) contrast, the development of exogenous agents is critical in targeting cancerous tumors. The current study demonstrates the feasibility of marine-oriented material, astaxanthin, as a biocompatible PA contrast agent. Both silicon tubing phantoms and ex vivo bladder tissues are tested at various concentrations (up to 5 mg/ml) of astaxanthin to quantitatively explore variations in PA responses. A Q-switched Nd : YAG laser (λ = 532 nm) in conjunction with a 5 MHz ultrasound transducer is employed to generate and acquire PA signals from the samples. The phantom results presented that the PA signal amplitudes increase linearly with the astaxanthin concentrations (threshold detection = 0.31 mg/ml). The tissue injected with astaxanthin yields up to 16-fold higher PA signals, compared with that with saline. Due to distribution of the injected astaxanthin, PAI can image the margin of astaxanthin boles as well as quantify their volume in 3D reconstruction. Further investigations on selective tumor targeting are required to validate astaxanthin as a potential biocompatible contrast agent for PAI-assisted bladder cancer detection. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Optical Methods and Instrumentation in Brain Imaging and Therapy

    CERN Document Server

    2013-01-01

    This book provides a comprehensive up-to-date review of optical approaches used in brain imaging and therapy. It covers a variety of imaging techniques including diffuse optical imaging, laser speckle imaging, photoacoustic imaging and optical coherence tomography. A number of laser-based therapeutic approaches are reviewed, including photodynamic therapy, fluorescence guided resection and photothermal therapy. Fundamental principles and instrumentation are discussed for each imaging and therapeutic technique. Represents the first publication dedicated solely to optical diagnostics and therapeutics in the brain Provides a comprehensive review of the principles of each imaging/therapeutic modality Reviews the latest advances in instrumentation for optical diagnostics in the brain Discusses new optical-based therapeutic approaches for brain diseases

  10. heuristically improved bayesian segmentation of brain mr images

    African Journals Online (AJOL)

    INTRODUCTION. Image segmentation is the process of dividing an image into its constituent non-overlapping components (Khayati, Vafadust et al. 2008; Wang ... analysis. Automatic segmentation of brain MR Images into its main tissues remains an inextricable problem in domain of medical image processing. First of all ...

  11. Advanced Pediatric Brain Imaging Research and Training Program

    Science.gov (United States)

    2017-10-01

    Award Number: W81XWH-11-2-0198 TITLE: Advanced Pediatric Brain Imaging Research and Training Program PRINCIPAL INVESTIGATOR: Catherine...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Advanced Pediatric Brain Imaging Research and Training Program 5b. GRANT NUMBER W81XWH-11-2-0198 5c. PROGRAM ...13. SUPPLEMENTARY NOTES 14. ABSTRACT The focus of our BRAIN training program over the past year of the project is to successfully convert the

  12. Agent-based brain modeling by means of hierarchical cooperative coevolution.

    Science.gov (United States)

    Maniadakis, Michail; Trahanias, Panos

    2009-01-01

    We address the development of brain-inspired models that will be embedded in robotic systems to support their cognitive abilities. We introduce a novel agent-based coevolutionary computational framework for modeling assemblies of brain areas. Specifically, self-organized agent structures are employed to represent brain areas. In order to support the design of agents, we introduce a hierarchical cooperative coevolutionary (HCCE) scheme that effectively specifies the structural details of autonomous, yet cooperating system components. The design process is facilitated by the capability of the HCCE-based design mechanism to investigate the performance of the model in lesion conditions. Interestingly, HCCE also provides a consistent mechanism to reconfigure (if necessary) the structure of agents, facilitating follow-up modeling efforts. Implemented models are embedded in a simulated robot to support its behavioral capabilities, also demonstrating the validity of the proposed computational framework.

  13. Magnetic resonance imaging with hyperpolarized agents: methods and applications

    Science.gov (United States)

    Adamson, Erin B.; Ludwig, Kai D.; Mummy, David G.; Fain, Sean B.

    2017-07-01

    In the past decade, hyperpolarized (HP) contrast agents have been under active development for MRI applications to address the twin challenges of functional and quantitative imaging. Both HP helium (3He) and xenon (129Xe) gases have reached the stage where they are under study in clinical research. HP 129Xe, in particular, is poised for larger scale clinical research to investigate asthma, chronic obstructive pulmonary disease, and fibrotic lung diseases. With advances in polarizer technology and unique capabilities for imaging of 129Xe gas exchange into lung tissue and blood, HP 129Xe MRI is attracting new attention. In parallel, HP 13C and 15N MRI methods have steadily advanced in a wide range of pre-clinical research applications for imaging metabolism in various cancers and cardiac disease. The HP [1-13C] pyruvate MRI technique, in particular, has undergone phase I trials in prostate cancer and is poised for investigational new drug trials at multiple institutions in cancer and cardiac applications. This review treats the methodology behind both HP gases and HP 13C and 15N liquid state agents. Gas and liquid phase HP agents share similar technologies for achieving non-equilibrium polarization outside the field of the MRI scanner, strategies for image data acquisition, and translational challenges in moving from pre-clinical to clinical research. To cover the wide array of methods and applications, this review is organized by numerical section into (1) a brief introduction, (2) the physical and biological properties of the most common polarized agents with a brief summary of applications and methods of polarization, (3) methods for image acquisition and reconstruction specific to improving data acquisition efficiency for HP MRI, (4) the main physical properties that enable unique measures of physiology or metabolic pathways, followed by a more detailed review of the literature describing the use of HP agents to study: (5) metabolic pathways in cancer and cardiac

  14. Whole-brain dynamic CT angiography and perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orrison, W.W. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Department of Medical Education, University of Nevada School of Medicine, Reno, NV (United States); Snyder, K.V.; Hopkins, L.N. [Department of Neurosurgery, Millard Fillmore Gates Circle Hospital, Buffalo, NY (United States); Roach, C.J. [School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Ringdahl, E.N. [Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV (United States); Nazir, R. [Shifa International Hospital, Islamabad (Pakistan); Hanson, E.H., E-mail: eric.hanson@amigenics.co [College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States)

    2011-06-15

    The availability of whole brain computed tomography (CT) perfusion has expanded the opportunities for analysing the haemodynamic parameters associated with varied neurological conditions. Examples demonstrating the clinical utility of whole-brain CT perfusion imaging in selected acute and chronic ischaemic arterial neurovascular conditions are presented. Whole-brain CT perfusion enables the detection and focused haemodynamic analyses of acute and chronic arterial conditions in the central nervous system without the limitation of partial anatomical coverage of the brain.

  15. Ultrasound contrast agent imaging : Real-time imaging of the superharmonics

    NARCIS (Netherlands)

    Peruzzini, D.; Viti, J.; Tortoli, P.; Verweij, M.D.; De Jong, N.; Vos, H.J.

    2015-01-01

    Currently, in medical ultrasound contrast agent (UCA) imaging the second harmonic scattering of the microbubbles is regularly used. This scattering is in competition with the signal that is caused by nonlinear wave propagation in tissue. It was reported that UCA imaging based on the third or higher

  16. Graphene-based nanomaterials as molecular imaging agents.

    Science.gov (United States)

    Garg, Bhaskar; Sung, Chu-Hsun; Ling, Yong-Chien

    2015-01-01

    Molecular imaging (MI) is a noninvasive, real-time visualization of biochemical events at the cellular and molecular level within tissues, living cells, and/or intact objects that can be advantageously applied in the areas of diagnostics, therapeutics, drug discovery, and development in understanding the nanoscale reactions including enzymatic conversions and protein-protein interactions. Consequently, over the years, great advancement has been made in the development of a variety of MI agents such as peptides, aptamers, antibodies, and various nanomaterials (NMs) including single-walled carbon nanotubes. Recently, graphene, a material popularized by Geim & Novoselov, has ignited considerable research efforts to rationally design and execute a wide range of graphene-based NMs making them an attractive platform for developing highly sensitive MI agents. Owing to their exceptional physicochemical and biological properties combined with desirable surface engineering, graphene-based NMs offer stable and tunable visible emission, small hydrodynamic size, low toxicity, and high biocompatibility and thus have been explored for in vitro and in vivo imaging applications as a promising alternative of traditional imaging agents. This review begins by describing the intrinsic properties of graphene and the key MI modalities. After which, we provide an overview on the recent advances in the design and development as well as physicochemical properties of the different classes of graphene-based NMs (graphene-dye conjugates, graphene-antibody conjugates, graphene-nanoparticle composites, and graphene quantum dots) being used as MI agents for potential applications including theranostics. Finally, the major challenges and future directions in the field will be discussed. © 2015 Wiley Periodicals, Inc.

  17. Brain MR image segmentation using NAMS in pseudo-color.

    Science.gov (United States)

    Li, Hua; Chen, Chuanbo; Fang, Shaohong; Zhao, Shengrong

    2017-12-01

    Image segmentation plays a crucial role in various biomedical applications. In general, the segmentation of brain Magnetic Resonance (MR) images is mainly used to represent the image with several homogeneous regions instead of pixels for surgical analyzing and planning. This paper proposes a new approach for segmenting MR brain images by using pseudo-color based segmentation with Non-symmetry and Anti-packing Model with Squares (NAMS). First of all, the NAMS model is presented. The model can represent the image with sub-patterns to keep the image content and largely reduce the data redundancy. Second, the key idea is proposed that convert the original gray-scale brain MR image into a pseudo-colored image and then segment the pseudo-colored image with NAMS model. The pseudo-colored image can enhance the color contrast in different tissues in brain MR images, which can improve the precision of segmentation as well as directly visual perceptional distinction. Experimental results indicate that compared with other brain MR image segmentation methods, the proposed NAMS based pseudo-color segmentation method performs more excellent in not only segmenting precisely but also saving storage.

  18. Quinone-fused porphyrins as contrast agents for photoacoustic imaging

    KAUST Repository

    Banala, Srinivas

    2017-06-27

    Photoacoustic (PA) imaging is an emerging non-invasive diagnostic modality with many potential clinical applications in oncology, rheumatology and the cardiovascular field. For this purpose, there is a high demand for exogenous contrast agents with high absorption coefficients in the optical window for tissue imaging, i.e. the near infrared (NIR) range between 680 and 950 nm. We herein report the photoacoustic properties of quinone-fused porphyrins inserted with different transition metals as new highly promising candidates. These dyes exhibit intense NIR absorption, a lack of fluorescence emission, and PA sensitivity in concentrations below 3 nmol mL. In this context, the highest PA signal was obtained with a Zn(ii) inserted dye. Furthermore, this dye was stable in blood serum and free thiol solution and exhibited negligible cell toxicity. Additionally, the Zn(ii) probe could be detected with an up to 3.2 fold higher PA intensity compared to the clinically most commonly used PA agent, ICG. Thus, further exploration of the \\'quinone-fusing\\' approach to other chromophores may be an efficient way to generate highly potent PA agents that do not fluoresce and shift their absorption into the NIR range.

  19. Shape Effects in Nanoparticle-Based Imaging Agents

    Science.gov (United States)

    Culver, Kayla Shani Brook

    At the nanoscale, material properties become highly size and shape dependent. These properties can be manipulated and exploited for a variety of biomedical applications, including sensing, drug delivery, diagnostics, and imaging. In particular, nanoparticles of different materials, sizes and shapes have been developed as high-performance contrast agents for optical, electron, and medical imaging. In this thesis, I focus on gold nanoparticles because they are widely used as contrast agents in multiple types of imaging modalities. Additionally, the surface of gold can be readily functionalized with ligands and the structure of the particles can be manipulated to modulate their performance as imaging agents. The properties of nanoparticles can generate contrast directly. For example, the light scattering properties of gold particles can be visualized in optical microscopy, the high electron density of gold produces contrast in electron microscopy, and the x-ray absorption properties of gold can be detected in medical x-ray and computed tomography imaging. Alternatively, the properties of the nanomaterial can be exploited to modulate the signal produced by other molecules that are bound to the particle surface. The light emission of molecular fluorophores can be quenched or dramatically increased by coupling to the optical field enhancements of gold nanoparticles, and the performance of gadolinium (Gd(III))-based magnetic resonance imaging (MRI) contrast agents can be increased by coupling to the rotational motion of nanoparticles. In this dissertation, I focus specifically on how the structure of star-shaped gold particles (nanostars) can be exploited as single-particle optical probes and to dramatically enhance the relaxivity of Gd(III) bound to the surface. Differential interference contrast (DIC) is a type of wide-field diffraction-limited optical microscopy that is commonly used by biologists to image cells without labels. Here, I demonstrate the DIC can be used

  20. Novel Nanotechnologies for Brain Cancer Therapeutics and Imaging.

    Science.gov (United States)

    Ferroni, Letizia; Gardin, Chiara; Della Puppa, Alessandro; Sivolella, Stefano; Brunello, Giulia; Scienza, Renato; Bressan, Eriberto; D'Avella, Domenico; Zavan, Barbara

    2015-11-01

    Despite progress in surgery, radiotherapy, and in chemotherapy, an effective curative treatment of brain cancer, specifically malignant gliomas, does not yet exist. The efficacy of current anti-cancer strategies in brain tumors is limited by the lack of specific therapies against malignant cells. Besides, the delivery of the drugs to brain tumors is limited by the presence of the blood-brain barrier. Nanotechnology today offers a unique opportunity to develop more effective brain cancer imaging and therapeutics. In particular, the development of nanocarriers that can be conjugated with several functional molecules including tumor-specific ligands, anticancer drugs, and imaging probes, can provide new devices which are able to overcome the difficulties of the classical strategies. Nanotechnology-based approaches hold great promise for revolutionizing brain cancer medical treatments, imaging, and diagnosis.

  1. Linear Gadolinium-Based Contrast Agents Are Associated With Brain Gadolinium Retention in Healthy Rats

    Science.gov (United States)

    Robert, Philippe; Violas, Xavier; Grand, Sylvie; Lehericy, Stéphane; Idée, Jean-Marc; Ballet, Sébastien; Corot, Claire

    2016-01-01

    Objectives The aim of this study was to evaluate Gd retention in the deep cerebellar nuclei (DCN) of linear gadolinium-based contrast agents (GBCAs) compared with a macrocyclic contrast agent. Materials and Methods The brain tissue retention of Gd of 3 linear GBCAs (gadobenate dimeglumine, gadopentetate dimeglumine, and gadodiamide) and a macrocyclic GBCA (gadoterate meglumine) was compared in healthy rats (n = 8 per group) that received 20 intravenous injections of 0.6 mmol Gd/kg (4 injections per week for 5 weeks). An additional control group with saline was included. T1-weighted magnetic resonance imaging was performed before injection and once a week during the 5 weeks of injections and for another 4 additional weeks after contrast period. Total gadolinium concentration was measured with inductively coupled plasma mass spectrometry. Blinded qualitative and quantitative evaluations of the T1 signal intensity in DCN were performed, as well as a statistical analysis on quantitative data. Results At completion of the injection period, all the linear contrast agents (gadobenate dimeglumine, gadopentetate dimeglumine, and gadodiamide) induced a significant increase in signal intensity in DCN, unlike the macrocyclic GBCA (gadoterate meglumine) or saline. The T1 hypersignal enhancement kinetic was fast for gadodiamide. Total Gd concentrations for the 3 linear GBCAs groups at week 10 were significantly higher in the cerebellum (1.21 ± 0.48, 1.67 ± 0.17, and 3.75 ± 0.18 nmol/g for gadobenate dimeglumine, gadopentetate dimeglumine, and gadodiamide, respectively) than with the gadoterate meglumine (0.27 ± 0.16 nmol/g, P dimeglumine, and gadopentetate dimeglumine to healthy rats were associated with progressive and significant T1 signal hyperintensity in the DCN, along with Gd deposition in the cerebellum. This is in contrast with the macrocyclic GBCA gadoterate meglumine for which no effect was observed. PMID:26606549

  2. Advanced Pediatric Brain Imaging Research Program

    Science.gov (United States)

    2016-10-01

    system, by creating and implementing methods for converting the existing in-classroom educational BRAIN seminars into self-directed online learning...confirm that online multimedia learning provides a highly engaging educational method to teaching complex subject matter on brain development, brain injury...Ongoing Visual Enhancements to BRAIN We continue to create, improve upon and implement multimedia objects (e.g. graphics, audio, animations ) throughout

  3. Nanoparticle Loaded Polymeric Microbubbles as Contrast Agents for Multimodal Imaging.

    Science.gov (United States)

    Teraphongphom, Nutte; Chhour, Peter; Eisenbrey, John R; Naha, Pratap C; Witschey, Walter R T; Opasanont, Borirak; Jablonowski, Lauren; Cormode, David P; Wheatley, Margaret A

    2015-11-03

    Ultrasound contrast agents are typically microbubbles (MB) with a gas core that is stabilized by a shell made of lipids, proteins, or polymers. The high impedance mismatch between the gas core and an aqueous environment produces strong contrast in ultrasound (US). Poly(lactic acid) (PLA) MB, previously developed in our laboratory, have been shown to be highly echogenic both in vitro and in vivo. Combining US with other imaging modalities such as fluorescence, magnetic resonance imaging (MRI), or computerized tomography (CT) could improve the accuracy of many US applications and provide more comprehensive diagnostic information. Furthermore, our MB have the capacity to house a drug in the PLA shell and create drug-loaded nanoparticles in situ when passing through an ultrasound beam. To create multimodal contrast agents, we hypothesized that the polymer shell of our PLA MB platform could accommodate additional payloads. In this study, we therefore modified our current MB by encapsulating nanoparticles including aqueous or organic quantum dots (QD), magnetic iron oxide nanoparticles (MNP), or gold nanoparticles (AuNP) to create bimodality platforms in a manner that minimally compromised the performance of each individual imaging technique.

  4. The use of contrast agent for imaging biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Dammer, J; Sopko, V; Jakubek, J [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Weyda, F, E-mail: jiri.dammer@utef.cvut.cz [Biological center of the Academy of Sciences of the Czech Republic, Institute of Entomology, Branisovska 31, CZ-37005 Ceske Budejovice (Czech Republic)

    2011-01-15

    The technique of X-ray transmission imaging has been available for over a century and is still among the fastest and easiest approaches to the studies of internal structure of biological samples. Recent advances in semiconductor technology have led to the development of new types of X-ray detectors with direct conversion of interacting X-ray photon to an electric signal. Semiconductor pixel detectors seem to be specially promising; compared to the film technique, they provide single-quantum and real-time digital information about the objects being studied. We describe the recently developed radiographic apparatus, equipped with Medipix2 semiconductor pixel detector. The detector is used as an imager that counts individual photons of ionizing radiation, emitted by an X-ray tube (micro- or nano-focus FeinFocus). Thanks to the wide dynamic range of the Medipix2 detector and its high spatial resolution better than 1{mu}m, the setup is particularly suitable for radiographic imaging of small biological samples, including in-vivo observations with contrast agent (Optiray). Along with the description of the apparatus we provide examples of the use iodine contrast agent as a tracer in various insects as model organisms. The motivation of our work is to develop our imaging techniques as non-destructive and non-invasive. Microradiographic imaging helps detect organisms living in a not visible environment, visualize the internal biological processes and also to resolve the details of their body (morphology). Tiny live insects are an ideal object for our studies.

  5. The use of contrast agent for imaging biological samples

    Science.gov (United States)

    Dammer, J.; Weyda, F.; Sopko, V.; Jakubek, J.

    2011-01-01

    The technique of X-ray transmission imaging has been available for over a century and is still among the fastest and easiest approaches to the studies of internal structure of biological samples. Recent advances in semiconductor technology have led to the development of new types of X-ray detectors with direct conversion of interacting X-ray photon to an electric signal. Semiconductor pixel detectors seem to be specially promising; compared to the film technique, they provide single-quantum and real-time digital information about the objects being studied. We describe the recently developed radiographic apparatus, equipped with Medipix2 semiconductor pixel detector. The detector is used as an imager that counts individual photons of ionizing radiation, emitted by an X-ray tube (micro- or nano-focus FeinFocus). Thanks to the wide dynamic range of the Medipix2 detector and its high spatial resolution better than 1μm, the setup is particularly suitable for radiographic imaging of small biological samples, including in-vivo observations with contrast agent (Optiray). Along with the description of the apparatus we provide examples of the use iodine contrast agent as a tracer in various insects as model organisms. The motivation of our work is to develop our imaging techniques as non-destructive and non-invasive. Microradiographic imaging helps detect organisms living in a not visible environment, visualize the internal biological processes and also to resolve the details of their body (morphology). Tiny live insects are an ideal object for our studies.

  6. AAZTA: an ideal chelating agent for the development of {sup 44}Sc PET imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Gabor; Szikra, Dezso; Trencsenyi, Gyoergy [Scanomed Ltd., Debrecen (Hungary); University of Debrecen, Medical Imaging Clinic (Hungary); Fekete, Aniko [University of Debrecen, Medical Imaging Clinic (Hungary); Garai, Ildiko [Scanomed Ltd., Debrecen (Hungary); Giani, Arianna M.; Negri, Roberto [Dipartimento di Scienze del Farmaco, Universita del Piemonte Orientale, Novara (Italy); Masciocchi, Norberto [Dipartimento di Scienza e Alta Tecnologia e To.Sca.Lab, Universita degli Studi dell' Insubria, Como (Italy); Maiocchi, Alessandro; Uggeri, Fulvio [Bracco Imaging spa, Bracco Research Centre, Colleretto Giacosa (Italy); Toth, Imre [Department of Inorganic and Analytical Chemistry, University of Debrecen (Hungary); Aime, Silvio [Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Centro di Imaging Molecolare e Preclinico, Universita degli Studi di Torino (Italy); Giovenzana, Giovanni B. [Dipartimento di Scienze del Farmaco, Universita del Piemonte Orientale, Novara (Italy); CAGE Chemicals srl, Novara (Italy); Baranyai, Zsolt [Bracco Imaging spa, Bracco Research Centre, Colleretto Giacosa (Italy); Department of Inorganic and Analytical Chemistry, University of Debrecen (Hungary)

    2017-02-13

    Unprecedented fast and efficient complexation of Sc{sup III} was demonstrated with the chelating agent AAZTA (AAZTA=1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)] amino-6-methylperhydro-1,4-d iazepine) under mild experimental conditions. The robustness of the {sup 44}Sc(AAZTA){sup -} chelate and conjugated biomolecules thereof is further shown by in vivo PET imaging in healthy and tumor mice models. The new results pave the way towards development of efficient Sc-based radiopharmaceuticals using the AAZTA chelator. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Evaluation of 7 {alpha}-O-IADPN as a new potential SPECT opioid receptor imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R.F.; Mao, S.Y. [Fujian Medical College, Fuzhou (China). Dept. of Nuclear Medicine; Tafani, J.A.M.; Coulais, Y.; Guiraud, R. [Hospital Purpan, Toulouse (France). Service Central de medicine Nucleaire; Zajac, J.M. [LPTF-CNRS, Toulouse (France)

    1998-03-01

    Full text: A new iodinated diprenorphine antagonist analogue, [{sup 123}I]7 {alpha}.-O-IADPN, [E] - 17-(cyclopropylmethyl) -4,5 (x-epoxy- 18,19-dihydro-3-hydroxy-6-methoxy-7 {alpha}-[1-(3-iodoallyl)oxy-1-methylethyl]-6,14-endo-ethenomorphinan for in vivo and in vitro studies as a potential central nervous system (CNS) opioid receptor imaging agent was developed. In vivo biodistribution and metabolism of 7 {alpha}-O-lADPN in rat demonstrated that 0.16% of the iodinated compound was presented in mouse brain with a degradation-resistant at the first 60 min, and that 36% of the total cerebral radioactivity and 63% of its specific binding to opioid receptors were observed 20 min after i.v. injection. The cerebral radioactivity in mouse brain concentrated in the basal ganglion and cortex, and displayed a remarkably high target-to-non-target ratio (cortex/cerebellum = 60 min post-injection). The in vitro binding studies showed that [{sup 123}I]7 {alpha}-O-IADPN binds non selectively to multiple opioid receptors {mu} = 8 K) with a very high affinity (Ki = 0.4 + 0.2 nM). Ex vivo autoradiography results in mouse further confirmed the high uptake and retention of this agent in basal ganglion region and cortex. The planar imaging of monkey brains after i.v. injection of [{sup 123}I]7 {alpha}-O-IADPN clearly displayed that multiple opioid receptors can be visualized. With the excellent in vitro affinity and in vivo stability to deiodination and high target-to-nontarget ratio, [{sup 123}I]7 {alpha}- O-IADPN appears to be useful as a CNS opioid receptor imaging probe for SPECT in primate and non-primate.

  8. MR imaging of the neonatal brain at 3 Tesla.

    Science.gov (United States)

    Rutherford, Mary; Malamateniou, Christina; Zeka, Julie; Counsell, Serena

    2004-01-01

    3 Telsa MR scanners are now becoming more widely available and 3 Telsa is likely to become the filed strength of choice for clinical imaging of the brain. The neonatal brain can be safely and successfully imaged at 3 Telsa. The improved signal to noise afforded by a higher field strength may be used to improve image quality or shorten acquisition times. This may be exploited for conventional T1 and T2 weighted imaging and also for advanced techniques such as diffusion tensor imaging, angiography and functional magnetic resonance studies.

  9. Appropriate Contrast Enhancement Measures for Brain and Breast Cancer Images.

    Science.gov (United States)

    Gupta, Suneet; Porwal, Rabins

    2016-01-01

    Medical imaging systems often produce images that require enhancement, such as improving the image contrast as they are poor in contrast. Therefore, they must be enhanced before they are examined by medical professionals. This is necessary for proper diagnosis and subsequent treatment. We do have various enhancement algorithms which enhance the medical images to different extents. We also have various quantitative metrics or measures which evaluate the quality of an image. This paper suggests the most appropriate measures for two of the medical images, namely, brain cancer images and breast cancer images.

  10. Appropriate Contrast Enhancement Measures for Brain and Breast Cancer Images

    Directory of Open Access Journals (Sweden)

    Suneet Gupta

    2016-01-01

    Full Text Available Medical imaging systems often produce images that require enhancement, such as improving the image contrast as they are poor in contrast. Therefore, they must be enhanced before they are examined by medical professionals. This is necessary for proper diagnosis and subsequent treatment. We do have various enhancement algorithms which enhance the medical images to different extents. We also have various quantitative metrics or measures which evaluate the quality of an image. This paper suggests the most appropriate measures for two of the medical images, namely, brain cancer images and breast cancer images.

  11. Fuzzy object models for newborn brain MR image segmentation

    Science.gov (United States)

    Kobashi, Syoji; Udupa, Jayaram K.

    2013-03-01

    Newborn brain MR image segmentation is a challenging problem because of variety of size, shape and MR signal although it is the fundamental study for quantitative radiology in brain MR images. Because of the large difference between the adult brain and the newborn brain, it is difficult to directly apply the conventional methods for the newborn brain. Inspired by the original fuzzy object model introduced by Udupa et al. at SPIE Medical Imaging 2011, called fuzzy shape object model (FSOM) here, this paper introduces fuzzy intensity object model (FIOM), and proposes a new image segmentation method which combines the FSOM and FIOM into fuzzy connected (FC) image segmentation. The fuzzy object models are built from training datasets in which the cerebral parenchyma is delineated by experts. After registering FSOM with the evaluating image, the proposed method roughly recognizes the cerebral parenchyma region based on a prior knowledge of location, shape, and the MR signal given by the registered FSOM and FIOM. Then, FC image segmentation delineates the cerebral parenchyma using the fuzzy object models. The proposed method has been evaluated using 9 newborn brain MR images using the leave-one-out strategy. The revised age was between -1 and 2 months. Quantitative evaluation using false positive volume fraction (FPVF) and false negative volume fraction (FNVF) has been conducted. Using the evaluation data, a FPVF of 0.75% and FNVF of 3.75% were achieved. More data collection and testing are underway.

  12. Brain MRI tumor image fusion combined with Shearlet and wavelet

    Science.gov (United States)

    Zhang, Changjiang; Fang, Mingchao

    2017-11-01

    In order to extract the effective information in different modalities of the tumor region in brain Magnetic resonance imaging (MRI) images, we propose a brain MRI tumor image fusion method combined with Shearlet and wavelet transform. First, the source images are transformed into Shearlet domain and wavelet domain. Second, the low frequency component of Shearlet domain is fused by Laplace pyramid decomposition. Then the low-frequency fusion image is obtained through inverse Shearlet transform. Third, the high frequency subimages in wavelet domain are fused. Then the high-frequency fusion image is obtained through inverse wavelet transform. Finally, the low-frequency fusion image and high-frequency fusion image are summated to get the final fusion image. Through experiments conducted on 10 brain MRI tumor images, the result shown that the proposed fusion algorithm has the best fusion effect in the evaluation indexes of spatial frequency, edge strength and average gradient. The main spatial frequency of 10 images is 29.22, and the mean edge strength and average gradient is 103.77 and 10.42. Compared with different fusion methods, we find that the proposed method effectively fuses the information of multimodal brain MRI tumor images and improves the clarity of the tumor area well.

  13. DNA as Sensors and Imaging Agents for Metal Ions

    Science.gov (United States)

    Xiang, Yu

    2014-01-01

    Increasing interests in detecting metal ions in many chemical and biomedical fields have created demands for developing sensors and imaging agents for metal ions with high sensitivity and selectivity. This review covers recent progress in DNA-based sensors and imaging agents for metal ions. Through both combinatorial selection and rational design, a number of metal ion-dependent DNAzymes and metal ion-binding DNA structures that can selectively recognize specific metal ions have been obtained. By attaching these DNA molecules with signal reporters such as fluorophores, chromophores, electrochemical tags, and Raman tags, a number of DNA-based sensors for both diamagnetic and paramagnetic metal ions have been developed for fluorescent, colorimetric, electrochemical, and surface Raman detections. These sensors are highly sensitive (with detection limit down to 11 ppt) and selective (with selectivity up to millions-fold) toward specific metal ions. In addition, through further development to simplify the operation, such as the use of “dipstick tests”, portable fluorometers, computer-readable discs, and widely available glucose meters, these sensors have been applied for on-site and real-time environmental monitoring and point-of-care medical diagnostics. The use of these sensors for in situ cellular imaging has also been reported. The generality of the combinatorial selection to obtain DNAzymes for almost any metal ion in any oxidation state, and the ease of modification of the DNA with different signal reporters make DNA an emerging and promising class of molecules for metal ion sensing and imaging in many fields of applications. PMID:24359450

  14. Mechanism of Chronic Pain in Rodent Brain Imaging

    Science.gov (United States)

    Chang, Pei-Ching

    Chronic pain is a significant health problem that greatly impacts the quality of life of individuals and imparts high costs to society. Despite intense research effort in understanding of the mechanism of pain, chronic pain remains a clinical problem that has few effective therapies. The advent of human brain imaging research in recent years has changed the way that chronic pain is viewed. To further extend the use of human brain imaging techniques for better therapies, the adoption of imaging technique onto the animal pain models is essential, in which underlying brain mechanisms can be systematically studied using various combination of imaging and invasive techniques. The general goal of this thesis is to addresses how brain develops and maintains chronic pain in an animal model using fMRI. We demonstrate that nucleus accumbens, the central component of mesolimbic circuitry, is essential in development of chronic pain. To advance our imaging technique, we develop an innovative methodology to carry out fMRI in awake, conscious rat. Using this cutting-edge technique, we show that allodynia is assoicated with shift brain response toward neural circuits associated nucleus accumbens and prefrontal cortex that regulate affective and cognitive component of pain. Taken together, this thesis provides a deeper understanding of how brain mediates pain. It builds on the existing body of knowledge through maximizing the depth of insight into brain imaging of chronic pain.

  15. MR fluid-attenuated inversion recovery imaging as routine brain T2-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Arakia, Yutaka; Ashikaga, Ryuichiro; Fujii, Koichi; Nishimura, Yasumasa; Ueda, Jun; Fujita, Norihiko

    1999-11-01

    We tried to investigate if magnetic resonance (MR) fluid-attenuated inversion recovery (FLAIR) imaging can be used as a routine brain screening examination instead of spin-echo T2-weighted imaging. Three hundred and ninety-four patients with clinically suspected brain diseases were randomly selected and examined with both brain MR FLAIR and T2-weighted imaging on the axial plane. These two imaging techniques were evaluated by two neuroradiologists as to which imaging was better for routine brain T2-weighted imaging. In 123 of 394 cases (31%), FLAIR imaging was superior to spin-echo T2-weighted imaging. Especially in cases with inflammatory diseases, traumatic diseases and demyelinating diseases, FLAIR imaging was particularly useful. Small lesions bordering cerebrospinal fluid (CSF) are often detected only by FLAIR imaging. In 259 cases (66%), including 147 normal cases (37%), they were equally evaluated. Only in 12 cases (3%) was conventional T2-weighted imaging superior to FLAIR imaging. Cerebrovascular lesions like cerebral aneurysm and Moyamoya disease could not be detected on FLAIR images because these structures were obscured by a low signal from the CSF. Also, because old infarctions tend to appear as low signal intensity on FLAIR images, the condition was sometimes hard to detect. Finally, FLAIR imaging could be used as routine brain T2-weighted imaging instead of conventional spin-echo T2-weighted imaging if these vascular lesions were watched.

  16. Issues and Problems in Brain Magnetic Resonance Imaging: An Overview

    Directory of Open Access Journals (Sweden)

    Novanto Yudistira

    2008-04-01

    Full Text Available There are many issues and problems in the brain magnetic resonance imaging (MRI area that haven’t solved or reached satisfying result yet. This paper presents an overview of the various issues and problems of the segmentation, correction, optimization, description and their application in MRI. The overview is started by describing the segmentation properties that are the most important and challenging in MRI brain manipulation. Then correction for reconstructing the brain MRI cortex, classification is utilized to classify the segmented brain image, and also review the uses of description is the great prospecting issue while some neurologist need the information resulted from brain imaging process including their potential problems from application applied by each technique. In each case, it is provided some general background information.

  17. An automated and simple method for brain MR image extraction

    Directory of Open Access Journals (Sweden)

    Zhu Zixin

    2011-09-01

    Full Text Available Abstract Background The extraction of brain tissue from magnetic resonance head images, is an important image processing step for the analyses of neuroimage data. The authors have developed an automated and simple brain extraction method using an improved geometric active contour model. Methods The method uses an improved geometric active contour model which can not only solve the boundary leakage problem but also is less sensitive to intensity inhomogeneity. The method defines the initial function as a binary level set function to improve computational efficiency. The method is applied to both our data and Internet brain MR data provided by the Internet Brain Segmentation Repository. Results The results obtained from our method are compared with manual segmentation results using multiple indices. In addition, the method is compared to two popular methods, Brain extraction tool and Model-based Level Set. Conclusions The proposed method can provide automated and accurate brain extraction result with high efficiency.

  18. Bioluminescent magnetic nanoparticles as potential imaging agents for mammalian spermatozoa.

    Science.gov (United States)

    Vasquez, Erick S; Feugang, Jean M; Willard, Scott T; Ryan, Peter L; Walters, Keisha B

    2016-03-17

    Nanoparticles have emerged as key materials for developing applications in nanomedicine, nanobiotechnology, bioimaging and theranostics. Existing bioimaging technologies include bioluminescent resonance energy transfer-conjugated quantum dots (BRET-QDs). Despite the current use of BRET-QDs for bioimaging, there are strong concerns about QD nanocomposites containing cadmium which exhibits potential cellular toxicity. In this study, bioluminescent composites comprised of magnetic nanoparticles and firefly luciferase (Photinus pyralis) are examined as potential light-emitting agents for imaging, detection, and tracking mammalian spermatozoa. Characterization was carried out using infrared spectroscopy, TEM and cryo-TEM imaging, and ζ-potential measurements to demonstrate the successful preparation of these nanocomposites. Binding interactions between the synthesized nanoparticles and spermatozoon were characterized using confocal and atomic/magnetic force microscopy. Bioluminescence imaging and UV-visible-NIR microscopy results showed light emission from sperm samples incubated with the firefly luciferase-modified nanoparticles. Therefore, these newly synthesized luciferase-modified magnetic nanoparticles show promise as substitutes for QD labeling, and can potentially also be used for in vivo manipulation and tracking, as well as MRI techniques. These preliminary data indicate that luciferase-magnetic nanoparticle composites can potentially be used for spermatozoa detection and imaging. Their magnetic properties add additional functionality to allow for manipulation, sorting, or tracking of cells using magnetic techniques.

  19. Functional Imaging of Dolphin Brain Metabolism and Blood Flow

    National Research Council Canada - National Science Library

    Ridgway, Sam; Finneran, James; Carder, Don; Keogh, Mandy; Van Bonn, William; Smith, Cynthia; Scadeng, Miriam; Dubowitz, David; Mattrey, Robert; Hoh, Carl

    2006-01-01

    This report documents the first use of magnetic resonance images (MRls) of living dolphins to register functional brain scans, allowing for the exploration of potential mechanisms of unihemispheric sleep...

  20. Blood-Brain Barrier Imaging in Human Neuropathologies

    Science.gov (United States)

    Veksler, Ronel; Shelef, Ilan; Friedman, Alon

    2014-01-01

    The blood–brain barrier (BBB) is essential for normal function of the brain, and its role in many brain pathologies has been the focus of numerous studies during the last decades. Dysfunction of the BBB is not only being shown in numerous brain diseases, but animal studies have indicated that it plays a direct key role in the genesis of neurovascular dysfunction and associated neurodegeneration. As such evidence accumulates, the need for robust and clinically applicable methods for minimally invasive assessment of BBB integrity is becoming urgent. This review provides an introduction to BBB imaging methods in the clinical scenario. First, imaging modalities are reviewed, with a focus on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). We then proceed to review image analysis methods, including quantitative and semi-quantitative methods. The advantages and limitations of each approach are discussed, and future directions and questions are highlighted. PMID:25453223

  1. Imaging of brain tumors with histological correlations. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Drevelegas, Antonios (ed.)

    2011-07-01

    This volume provides a deeper understanding of the diagnosis of brain tumors by correlating radiographic imaging features with the underlying pathological abnormalities. All modern imaging modalities are used to complete a diagnostic overview of brain tumors with emphasis on recent advances in diagnostic neuroradiology. High-quality illustrations depicting common and uncommon imaging characteristics of a wide range of brain tumors are presented and analysed, drawing attention to the ways in which these characteristics reflect different aspects of pathology. Important theoretical considerations are also discussed. Since the first edition, chapters have been revised and updated and new material has been added, including detailed information on the clinical application of functional MRI and diffusion tensor imaging. Radiologists and other clinicians interested in the current diagnostic approach to brain tumors will find this book to be an invaluable and enlightening clinical tool. (orig.)

  2. Functional Imaging of Dolphin Brain Metabolism and Blood Flow

    National Research Council Canada - National Science Library

    Ridgway, Sam; Finneran, James; Carder, Don; Keogh, Mandy; Van Bonn, William; Smith, Cynthia; Scadeng, Miriam; Dubowitz, David; Mattrey, Robert; Hoh, Carl

    2006-01-01

    .... Diazepam has been shown to induce unihemispheric slow waves (USW), therefore we used functional imaging of dolphins with and without diazepam to observe hemispheric differences in brain metabolism and blood flow...

  3. A Unified Framework for Brain Segmentation in MR Images

    Directory of Open Access Journals (Sweden)

    S. Yazdani

    2015-01-01

    Full Text Available Brain MRI segmentation is an important issue for discovering the brain structure and diagnosis of subtle anatomical changes in different brain diseases. However, due to several artifacts brain tissue segmentation remains a challenging task. The aim of this paper is to improve the automatic segmentation of brain into gray matter, white matter, and cerebrospinal fluid in magnetic resonance images (MRI. We proposed an automatic hybrid image segmentation method that integrates the modified statistical expectation-maximization (EM method and the spatial information combined with support vector machine (SVM. The combined method has more accurate results than what can be achieved with its individual techniques that is demonstrated through experiments on both real data and simulated images. Experiments are carried out on both synthetic and real MRI. The results of proposed technique are evaluated against manual segmentation results and other methods based on real T1-weighted scans from Internet Brain Segmentation Repository (IBSR and simulated images from BrainWeb. The Kappa index is calculated to assess the performance of the proposed framework relative to the ground truth and expert segmentations. The results demonstrate that the proposed combined method has satisfactory results on both simulated MRI and real brain datasets.

  4. Structural brain imaging in diabetes : A methodological perspective

    NARCIS (Netherlands)

    Jongen, Cynthia; Biessels, Geert Jan

    2008-01-01

    Brain imaging provides information on brain anatomy and function and progression of cerebral abnormalities can be monitored. This may provide insight into the aetiology of diabetes related cerebral disorders. This paper focuses on the methods for the assessment of white matter hyperintensities and

  5. Nanoparticles as magnetic resonance imaging contrast agents for vascular and cardiac diseases

    NARCIS (Netherlands)

    Chen, Wei; Cormode, David P.; Fayad, Zahi A.; Mulder, Willem J. M.

    2011-01-01

    Advances in nanoparticle contrast agents for molecular imaging have made magnetic resonance imaging a promising modality for noninvasive visualization and assessment of vascular and cardiac disease processes. This review provides a description of the various nanoparticles exploited for imaging

  6. Brain imaging in the context of food perception and eating.

    Science.gov (United States)

    Hollmann, Maurice; Pleger, Burkhard; Villringer, Arno; Horstmann, Annette

    2013-02-01

    Eating behavior depends heavily on brain function. In recent years, brain imaging has proved to be a powerful tool to elucidate brain function and brain structure in the context of eating. In this review, we summarize recent findings in the fast growing body of literature in the field and provide an overview of technical aspects as well as the basic brain mechanisms identified with imaging. Furthermore, we highlight findings linking neural processing of eating-related stimuli with obesity. The consumption of food is based on a complex interplay between homeostatic and hedonic mechanisms. Several hormones influence brain activity to regulate food intake and interact with the brain's reward circuitry, which is partly mediated by dopamine signaling. Additionally, it was shown that food stimuli trigger cognitive control mechanisms that incorporate internal goals into food choice. The brain mechanisms observed in this context are strongly influenced by genetic factors, sex and personality traits. Overall, a complex picture arises from brain-imaging findings, because a multitude of factors influence human food choice. Although several key mechanisms have been identified, there is no comprehensive model that is able to explain the behavioral observations to date. Especially a careful characterization of patients according to genotypes and phenotypes could help to better understand the current and future findings in neuroimaging studies.

  7. Unsupervised Neural Techniques Applied to MR Brain Image Segmentation

    Directory of Open Access Journals (Sweden)

    A. Ortiz

    2012-01-01

    Full Text Available The primary goal of brain image segmentation is to partition a given brain image into different regions representing anatomical structures. Magnetic resonance image (MRI segmentation is especially interesting, since accurate segmentation in white matter, grey matter and cerebrospinal fluid provides a way to identify many brain disorders such as dementia, schizophrenia or Alzheimer’s disease (AD. Then, image segmentation results in a very interesting tool for neuroanatomical analyses. In this paper we show three alternatives to MR brain image segmentation algorithms, with the Self-Organizing Map (SOM as the core of the algorithms. The procedures devised do not use any a priori knowledge about voxel class assignment, and results in fully-unsupervised methods for MRI segmentation, making it possible to automatically discover different tissue classes. Our algorithm has been tested using the images from the Internet Brain Image Repository (IBSR outperforming existing methods, providing values for the average overlap metric of 0.7 for the white and grey matter and 0.45 for the cerebrospinal fluid. Furthermore, it also provides good results for high-resolution MR images provided by the Nuclear Medicine Service of the “Virgen de las Nieves” Hospital (Granada, Spain.

  8. Advanced Pediatric Brain Imaging Research and Training Program

    Science.gov (United States)

    2013-10-01

    as an official Department of the Army position , policy or decision unless so designated by other documentation. REPORT DOCUMENTATION PAGE Form...Imaging biomarkers of outcome in the developing preterm brain. Lancet Neurol. 2009 Nov;8(11):1042-55. Epub 2009 Sep 30. 4. Mathur AM, Neil JJ, Inder...TE.Understanding brain injury and neurodevelopmental disabilities in the preterm infant: the evolving role of advanced magnetic resonance imaging.Semin

  9. Basal ganglia infarction demonstrated by radionuclide brain imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, E.E.; Schacht, R.A.; Domstad, P.A.; DeLand, F.H.

    1982-11-01

    Four cases of basal ganglia infarction demonstrated by radionuclide brain imaging are presented. Bilateral basal ganglia infarctions in two patients were probably related to methanol intoxication and meningoencephalitis, and unilateral basal ganglia infarctions in two other patients were presumably due to cerebral atherosclerosis and/or hypertension. Various causes and mechanisms of basal ganglia infarction as well as positive findings of radionuclide brain imaging are briefly reviewed.

  10. Diagnosing Autism Spectrum Disorder through Brain Functional Magnetic Resonance Imaging

    Science.gov (United States)

    2016-03-01

    Diagnosing Autism Spectrum Disorder through Brain Functional Magnetic Resonance Imaging THESIS MARCH 2016 Kyle A. Palko, Second Lieutenant, USAF AFIT...declared a work of the U.S. Government and is not subject to copyright protection in the United States. AFIT-ENC-MS-16-M-123 DIAGNOSING AUTISM SPECTRUM...PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENC-MS-16-M-123 DIAGNOSING AUTISM SPECTRUM DISORDER THROUGH BRAIN FUNCTIONAL MAGNETIC RESONANCE IMAGING Kyle

  11. The Potential of Using Brain Images for Authentication

    Directory of Open Access Journals (Sweden)

    Fanglin Chen

    2014-01-01

    Full Text Available Biometric recognition (also known as biometrics refers to the automated recognition of individuals based on their biological or behavioral traits. Examples of biometric traits include fingerprint, palmprint, iris, and face. The brain is the most important and complex organ in the human body. Can it be used as a biometric trait? In this study, we analyze the uniqueness of the brain and try to use the brain for identity authentication. The proposed brain-based verification system operates in two stages: gray matter extraction and gray matter matching. A modified brain segmentation algorithm is implemented for extracting gray matter from an input brain image. Then, an alignment-based matching algorithm is developed for brain matching. Experimental results on two data sets show that the proposed brain recognition system meets the high accuracy requirement of identity authentication. Though currently the acquisition of the brain is still time consuming and expensive, brain images are highly unique and have the potential possibility for authentication in view of pattern recognition.

  12. Gadolinium chloride as a contrast agent for imaging wood composite components by magnetic resonance

    Science.gov (United States)

    Thomas L. Eberhardt; Chi-Leung So; Andrea Protti; Po-Wah So

    2009-01-01

    Although paramagnetic contrast agents have an established track record in medical uses of magnetic resonance imaging (MRI), only recently has a contrast agent been used for enhancing MRI images of solid wood specimens. Expanding on this concept, wood veneers were treated with a gadolinium-based contrast agent and used in a model system comprising three-ply plywood...

  13. Targeted Multifunctional Nanoparticles cure and image Brain Tumors: Selective MRI Contrast Enhancement and Photodynamic Therapy

    Science.gov (United States)

    Kopelman, Raoul

    2008-03-01

    Aimed at targeted therapy and imaging of brain tumors, our approach uses targeted, multi-functional nano-particles (NP). A typical nano-particle contains a biologically inert, non-toxic matrix, biodegradable and bio-eliminable over a long time period. It also contains active components, such as fluorescent chemical indicators, photo-sensitizers, MRI contrast enhancement agents and optical imaging dyes. In addition, its surface contains molecular targeting units, e.g. peptides or antibodies, as well as a cloaking agent, to prevent uptake by the immune system, i.e. enabling control of the plasma residence time. These dynamic nano-platforms (DNP) contain contrast enhancement agents for the imaging (MRI, optical, photo-acoustic) of targeted locations, i.e. tumors. Added to this are targeted therapy agents, such as photosensitizers for photodynamic therapy (PDT). A simple protocol, for rats implanted with human brain cancer, consists of tail injection with DNPs, followed by 5 min red light illumination of the tumor region. It resulted in excellent cure statistics for 9L glioblastoma.

  14. Three-dimensional microtomographic imaging of human brain cortex

    CERN Document Server

    Mizutania, Ryuta; Uesugi, Kentaro; Ohyama, Masami; Takekoshi, Susumu; Osamura, R Yoshiyuki; Suzuki, Yoshio

    2016-01-01

    This paper describes an x-ray microtomographic technique for imaging the three-dimensional structure of the human cerebral cortex. Neurons in the brain constitute a neural circuit as a three-dimensional network. The brain tissue is composed of light elements that give little contrast in a hard x-ray transmission image. The contrast was enhanced by staining neural cells with metal compounds. The obtained structure revealed the microarchitecture of the gray and white matter regions of the frontal cortex, which is responsible for the higher brain functions.

  15. Brain tumor classification of microscopy images using deep residual learning

    Science.gov (United States)

    Ishikawa, Yota; Washiya, Kiyotada; Aoki, Kota; Nagahashi, Hiroshi

    2016-12-01

    The crisis rate of brain tumor is about one point four in ten thousands. In general, cytotechnologists take charge of cytologic diagnosis. However, the number of cytotechnologists who can diagnose brain tumors is not sufficient, because of the necessity of highly specialized skill. Computer-Aided Diagnosis by computational image analysis may dissolve the shortage of experts and support objective pathological examinations. Our purpose is to support a diagnosis from a microscopy image of brain cortex and to identify brain tumor by medical image processing. In this study, we analyze Astrocytes that is a type of glia cell of central nerve system. It is not easy for an expert to discriminate brain tumor correctly since the difference between astrocytes and low grade astrocytoma (tumors formed from Astrocyte) is very slight. In this study, we present a novel method to segment cell regions robustly using BING objectness estimation and to classify brain tumors using deep convolutional neural networks (CNNs) constructed by deep residual learning. BING is a fast object detection method and we use pretrained BING model to detect brain cells. After that, we apply a sequence of post-processing like Voronoi diagram, binarization, watershed transform to obtain fine segmentation. For classification using CNNs, a usual way of data argumentation is applied to brain cells database. Experimental results showed 98.5% accuracy of classification and 98.2% accuracy of segmentation.

  16. A Novel imaging agent for acetylcholinesterase: 2-[F-18]fluoro-CP-118,954

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Y. K.; Choi, Y. S; Baek, J. Y.; Lee, K. H.; Choi, Y.; Kim, B. T [Sungkyunkwan University School of Medicine, Suwon (Korea, Republic of); Park, E. Y.; Kim, Y. R.; Kim, S. E [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2004-07-01

    AcetyIcholinesterase (AChE) is an important cholinergic marker for the diagnosis of Alzheimer's disease. Although many AChE inhibitors were developed as radioligands for AChE imaging, most of them showed a uniform regional brain distribution. In this study, 2-fluoro-CP-118,954 with excellent anti-AChE activity (IC{sub 50} = 0.74 nM) was prepared as the radioligand, 2-[F-18]fluoro-CP-118,954 ([F-l8]) and evaluated for AChE imaging. [F-l8] was prepared by reductive alkylation of CP-144,885 (Pfizer Inc. U.S.A.) with 2-[F-l8]fIuorobenzaldehyde at 130 .deg. for 15 min, followed by HPLC purification. Mice were injected with the radioligand [F-18] via tail vein. At the indicated time points (5, 15, 30, 60, 90 and 120 min), samples of bone and brain tissues were removed, weighed, and counted. Blocking experiments were carried out in mice by coinjection of the radioligand with, a dopamine receptor antagonist, or a sigma receptor agonist, and samples of brain tissues were collected at 60 min postinjection, weighed and counted. The radioligand [F-l8] was synthesized in 20-35% radiochemical yield and with high specific activity (40-42 GBq/mol). Tissue distribution studies demonstrated that the regional brain distribution of [F-18] was welI correlated with the known density of AChE in mouse brain, with the highest striatum to cerebellum uptake ratio (4.5) at 60 min postinjection. The high level of uptake was also shown at all time points in the olfactory tubercle that is known to have the dopaminergic neurons and also have high AChE staining in rat brain. The uptake in both the striatum and olfactory tubercle was not blocked by either dopamine receptor antagonists or a sigma receptor agonist. On the other hand, significant blocking of the uptake by suggested high specific binding of [F-l8] to AChE. This study demonstrated that [F-18] is a suitable imaging agent for AChE.

  17. Whole brain imaging with Serial Two-Photon Tomography

    Directory of Open Access Journals (Sweden)

    Stephen P Amato

    2016-03-01

    Full Text Available Imaging entire mouse brains at submicron resolution has historically been a challenging undertaking and largely confined to the province of dedicated atlasing initiatives. The has limited systematic investigations into important areas of neuroscience, such as neural circuits, brain mapping and neurodegeneration. In this paper, we describe in detail Serial Two-Photon (STP tomography, a robust, reliable method for imaging entire brains with histological detail. We provide examples of how the basic methodology can be extended to other imaging modalities, such as optical coherence tomography, in order to provide unique contrast mechanisms. Furthermore we provide a survey of the research that STP tomography has enabled in the field of neuroscience, provide examples of how this technology enables quantitative whole brain studies, and discuss the current limitations of STP tomography-based approaches

  18. Characterization of nanoparticle-based contrast agents for molecular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Liang, E-mail: shanli@mail.nih.gov; Chopra, Arvind; Leung, Kam; Eckelman, William C. [National Institutes of Health, Molecular Imaging and Contrast Agent Database, National Center for Biotechnology Information, National Library of Medicine (United States); Menkens, Anne E. [National Institutes of Health, National Cancer Institute (United States)

    2012-09-15

    The development of molecular imaging agents is currently undergoing a dramatic expansion. As of October 2011, {approx}4,800 newly developed agents have been synthesized and characterized in vitro and in animal models of human disease. Despite this rapid progress, the transfer of these agents to clinical practice is rather slow. To address this issue, the National Institutes of Health launched the Molecular Imaging and Contrast Agents Database (MICAD) in 2005 to provide freely accessible online information regarding molecular imaging probes and contrast agents for the imaging community. While compiling information regarding imaging agents published in peer-reviewed journals, the MICAD editors have observed that some important information regarding the characterization of a contrast agent is not consistently reported. This makes it difficult for investigators to evaluate and meta-analyze data generated from different studies of imaging agents, especially for the agents based on nanoparticles. This article is intended to serve as a guideline for new investigators for the characterization of preclinical studies performed with nanoparticle-based MRI contrast agents. The common characterization parameters are summarized into seven categories: contrast agent designation, physicochemical properties, magnetic properties, in vitro studies, animal studies, MRI studies, and toxicity. Although no single set of parameters is suitable to define the properties of the various types of contrast agents, it is essential to ensure that these agents meet certain quality control parameters at the preclinical stage, so that they can be used without delay for clinical studies.

  19. Brain SPECT imaging in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Krausz, Y.; Yaffe, S.; Atlan, H. (Hadassah Univ. Hospital, Jerusalem (Israel). Dept. of Medical Biophysics and Nuclear Medicine); Cohen, D. (Hadassah Univ. Hospital, Jerusalem (Israel). Dept. of Radiology); Konstantini, S. (Hadassah Univ. Hospital, Jerusalem (Israel). Dept. of Neurosurgery); Meiner, Z. (Hadassah Univ. Hospital, Jerusalem (Israel). Dept. of Neurology)

    1991-06-01

    Temporal lobe epilepsy is diagnosed by clinical symptoms and signs and by localization of an epileptogenic focus. A brain SPECT study of two patients with temporal lobe epilepsy, using {sup 99m}Tc-HMPAO, was used to demonstrate a perfusion abnormality in the temporal lobe, while brain CT and MRI were non-contributory. The electroencephalogram, though abnormal, did not localize the diseased area. The potential role of the SPECT study in diagnosis and localization of temporal lobe epilepsy is discussed. (orig.).

  20. SPECT imaging of pulmonary emboli with radiolabeled thrombus-specific imaging agents.

    Science.gov (United States)

    Morris, Timothy A

    2010-11-01

    The safe and accurate diagnosis of acute pulmonary embolism (PE) remains challenging, and many PE-related deaths still occur before the detection of PE. Current techniques detect PE as "negative images," ie, the absence of contrast or downstream perfusion. There would be advantages to obtaining "positive images" of PE, by targeting imaging agents to components that are present primarily on thromboemboli. In addition to providing alternative means of diagnosing acute PE, they would also enable acute PE to be distinguished from other types of pulmonary arterial obstruction, such as unresolved intravascular defects attributable to previous PE. Positive images of PE require imaging agents to bind onto target antigens that are present predominantly on thromboemboli. The "D dimer" regions of polymerized fibrin are present in high concentrations on thromboemboli and are sufficiently accessible to binding. (99m)Tc-lableled anti-D-dimer deimmunized monoclonal antibody Fab' fragments (DI-DD-3B6/22-80B3) bind specifically to thromboemboli, with a thrombus: blood labeling ratio that allows scintigraphic detection. Another thrombus-specific imaging agent is (99m)Tc-labeled apcitide, a synthetic peptide that binds with a high affinity and specificity to the glycoprotein IIb/IIIa receptor on the membrane of activated platelets. Both of these agents have enabled the detection of lower extremity deep vein thrombi by planar scintigraphy. However, even highly radiolabeled PEs are difficult to distinguish by planar scintigraphy from the large blood pool in the heart and lungs. The spatial and contrast resolution inherent to single-photon emission computed tomography (SPECT) scanning allow the in situ imaging of pulmonary emboli that have been bound by radiolabeled thrombus-specific imaging agents. Preliminary trials in humans with acute PE have shown that the emboli can be detected after intravenous administration of (99m)Tc-lableled anti-D dimer, followed by SPECT scanning. Although

  1. Gadolinium-containing endohedral fullerenes: structures and function as magnetic resonance imaging (MRI) agents.

    Science.gov (United States)

    Ghiassi, Kamran B; Olmstead, Marilyn M; Balch, Alan L

    2014-05-28

    Gadolinium-containing endohedral fullerenes represent a new class of effective relaxation agents for magnetic resonance imaging (MRI). The range of different structures possible for this class of molecules and their properties as MRI agents are reviewed here.

  2. Advanced Pediatric Brain Imaging Research and Training Program

    Science.gov (United States)

    2015-10-01

    the BRAIN program has significant training benefits for healthcare providers across multiple specialties and subspecialties. 2 BODY The focus of...with or without contrast agents and arterial spin labeling, along with clinical applications. Finally, module 15 walks learners through the concepts...behind and clinical application of magnetic resonance spectroscopy including how to interpret NMR Spectra (electron shielding, spin spin coupling

  3. The traveling heads: multicenter brain imaging at 7 Tesla

    NARCIS (Netherlands)

    Voelker, M.N.; Kraff, O.; Kraff, O.; Brenner, D.; Wollrab, A.; Weinberger, O.; Berger, M.C.; Robinson, S.; Bogner, W.; Wiggins, C.; Trampel, R.; Stöcker, T.; Niendorf, T.; Quick, H.H.; Norris, David Gordon; Ladd, M.E.; Speck, O.

    2016-01-01

    Objective This study evaluates the inter-site and intra-site reproducibility of 7 Tesla brain imaging and compares it to literature values for other field strengths. Materials and methods The same two subjects were imaged at eight different 7 T sites. MP2RAGE, TSE, TOF, SWI, EPI as well as B1 and B0

  4. Imaging brain tumor proliferative activity with [I-124]iododeoxyuridine

    NARCIS (Netherlands)

    Blasberg, RG; Roelcke, U; Weinreich, R; Beattie, B; von Ammon, K; Yonekawa, Y; Landolt, H; Guenther, [No Value; Crompton, NEA; Vontobel, P; Missimer, J; Maguire, RP; Koziorowski, J; Knust, EJ; Finn, RD; Leenders, KL

    2000-01-01

    Iododeoxyuridine (IUdR) uptake and retention was imaged by positron emission tomography (PET) at 0-48 min and 24 h after administration of 28.0-64.4 MBq (0.76-1.74 mCi) of [I-124]IUdR in 20 patients with brain tumors, including meningiomas and gliomas, The PET images were directly compared with

  5. heuristically improved bayesian segmentation of brain mr images

    African Journals Online (AJOL)

    Therefore, finding automatic methods for segmenting images appears to be mandatory (Kumar and. Arthanariee 2014; Rajchl, Baxter et al. 2014; Valverde, Oliver et al. 2014). Nowadays, Magnetic Resonance Imaging (MRI) is a prevalent way of realizing human brain and mostly is utilized in diagnostics and therapeutics.

  6. Applications of nanotechnology to imaging and therapy of brain tumors.

    Science.gov (United States)

    Mohs, Aaron M; Provenzale, James M

    2010-08-01

    In the past decade, numerous advances in the understanding of brain tumor physiology, tumor imaging, and tumor therapy have been attained. In some cases, these advances have resulted from refinements of pre-existing technologies (eg, improvements of contrast-enhanced magnetic resonance imaging). In other instances, advances have resulted from development of novel technologies. The development of nanomedicine (ie, applications of nanotechnology to the field of medicine) is an example of the latter. In this review, the authors explain the principles that underlay nanoparticle design and function as well as the means by which nanoparticles can be used for imaging and therapy of brain tumors. Copyright 2010 Elsevier Inc. All rights reserved.

  7. In vivo PET imaging of brain nicotinic cholinergic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Bottlaender, M.; Valette, H.; Saba, W.; Schollhorn-Peyronneau, M.A.; Dolle, F.; Syrota, A. [Service Hospitalier Frederic Joliot (CEA/DSV/DRM), 91 - Orsay (France)

    2006-07-01

    Neuronal acetylcholine receptors (nAChRs) are widely distributed throughout the central nervous system where they modulate a number of CNS functions including neurotransmitter release, cognitive function, anxiety, analgesia and control of cerebral blood flow. In the brain, a major subtype is composed of the {alpha}4{beta}2 subunit combination. Density of this subtype has been shown to be decreased in patients with neuro-degenerative disease such as Alzheimer and Parkinson's disease (AD and PD), and mutated receptors has been described in some familial epilepsy. Thus, in vivo mapping of the nicotinic nAChRs by Positron Emission Tomography (PET) are of great interest to monitor the evolution of these pathologies and changes in the neuronal biochemistry induced by therapeutic agents. Recently, a new compound, 3-[2(S)-2-azetidinyl-methoxy]pyridine (A-85380) has been synthesised and labelled with fluorine-18, [{sup 18}F]fluoro-A-85380 (Dolle et al., 1999). The [{sup 18}F]fluoro-A-85380 has been shown to bind with high affinity t o nAChRs in vitro (Saba et al., 2004), and its toxicity was low and compatible with it s use at tracer dose in human PET studies (Valette, 2002). PET studies in baboons showed that, after in vivo administration of [ {sup 18}F]fluoro-A-85380 at a tracer dose, the distribution of the radioactivity in the brain reflect the distribution of the < 4R2 nAChRs. Competition and pre-blocking studies, using nicotinic agonists, confirm that the radiotracer binds specifically to the heteromeric nAChRs in the brain (Valette et al., 1999). The in vivo, characteristics of the [{sup 18}F]fluoro-A-8538 0 combined with its low toxicity make possible the imaging of the nicotinic receptor s in human by PET (Bottlaender 2003). Studies were performed in healthy non-smoker volunteers to evaluate the brain kinetics of [{sup 18}F]fluoro-A-85380 and to assess the quantification of its nAChRs binding in the human brain with PET (Gallezot et a., 2005). The [{sup 18}F

  8. Image guided constitutive modeling of the silicone brain phantom

    Science.gov (United States)

    Puzrin, Alexander; Skrinjar, Oskar; Ozan, Cem; Kim, Sihyun; Mukundan, Srinivasan

    2005-04-01

    The goal of this work is to develop reliable constitutive models of the mechanical behavior of the in-vivo human brain tissue for applications in neurosurgery. We propose to define the mechanical properties of the brain tissue in-vivo, by taking the global MR or CT images of a brain response to ventriculostomy - the relief of the elevated intracranial pressure. 3D image analysis translates these images into displacement fields, which by using inverse analysis allow for the constitutive models of the brain tissue to be developed. We term this approach Image Guided Constitutive Modeling (IGCM). The presented paper demonstrates performance of the IGCM in the controlled environment: on the silicone brain phantoms closely simulating the in-vivo brain geometry, mechanical properties and boundary conditions. The phantom of the left hemisphere of human brain was cast using silicon gel. An inflatable rubber membrane was placed inside the phantom to model the lateral ventricle. The experiments were carried out in a specially designed setup in a CT scanner with submillimeter isotropic voxels. The non-communicative hydrocephalus and ventriculostomy were simulated by consequently inflating and deflating the internal rubber membrane. The obtained images were analyzed to derive displacement fields, meshed, and incorporated into ABAQUS. The subsequent Inverse Finite Element Analysis (based on Levenberg-Marquardt algorithm) allowed for optimization of the parameters of the Mooney-Rivlin non-linear elastic model for the phantom material. The calculated mechanical properties were consistent with those obtained from the element tests, providing justification for the future application of the IGCM to in-vivo brain tissue.

  9. Brain magnetic resonance imaging findings in relapsing neuromyelitis optica.

    Science.gov (United States)

    Cabrera-Gómez, José A; Quevedo-Sotolongo, L; González-Quevedo, A; Lima, S; Real-González, Y; Cristófol-Corominas, M; Romero-García, K; Ugarte-Sánchez, C; Jordán-González, J; de la Nuez, J E González; Lahera, J García; Tellez, R; Pedroso-Ibañez, I; Roca, R Rodríguez; Cabrera-Núñez, A Y

    2007-03-01

    Some studies showed abnormalities in brain magnetic resonance imaging (MRI) of relapsing neuromyelitis optica (R-NMO) from 12 to 46%. These abnormalities are described as compatible/non-compatible with multiple sclerosis (MS). To describe the abnormal brain MRI lesions in R-NMO with imaging studies conducted with more sensitive white matter change techniques. Thirty patients with R-NMO were selected. All MRI brain studies were performed with a 1.5-T Siemens MRI system according to the Standardized MR Imaging Protocol for Multiple Sclerosis from the Consortium of MS Centers Consensus Guidelines. Brain MRI images were evaluated in 29 R-NMO cases because in one case the MRI images were not appropriate for the study. Of these 29 brain MRI studies, 19 cases (65.5%) had at least one or more lesions (1-57) and 10 were negative (34.4%). Brain MRI findings in 19 cases were characterized in T2/fluid-attenuated inversion-recovery (FLAIR) by the presence of subcortical/deep white matter lesions in 16 (84.2%) cases (1-50), most of them 3 mm, were observed in 4 (21.05%) cases without cerebellar involvement. T1 studies demonstrated absence of hypointense regions. Optic nerve enhancement was observed in 6/19 patients (31.5%). None of the brain MRI abnormalities observed were compatible with Barkhof et al. criteria of MS. This study, based on a Cuban patient population, with long duration of disease, good sample size and detailed characterization by MRI, demonstrated the brain MRI pattern of R-NMO patients, which is different from MS.

  10. Steroid hormones and brain development: some guidelines for understanding actions of pseudohormones and other toxic agents

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, B.S.

    1987-10-01

    Gonadal, adrenal, and thyroid hormones affect the brain directly, and the sensitivity to hormones begins in embryonic life with the appearance of hormone receptor sites in discrete populations of neurons. Because the secretion of hormones is also under control by its neural and pituitary targets, the brain-endocrine axis during development is in a delicately balanced state that can be upset in various ways, and any agent that disrupts normal hormone secretion can upset normal brain development. Moreover, exogenous substances that mimic the actions of natural hormones can also play havoc with CNS development and differentiation. This paper addresses these issues in the following order: First, actions of glucocorticoids on the developing nervous system related to cell division dendritic growth and neurotransmitter phenotype will be presented followed by a discussion of the developmental effects of synthetic steroids. Second, actions of estrogens related to brain sexual differentiation will be described, followed by a discussion of the actions of the nonsteroidal estrogen, diethylstilbestrol, as an example of exogenous estrogenic substances. The most important aspect of the potency of exogenous estrogens appears to be the degree to which they either bypass protective mechanisms or are subject to transformations to more active metabolites. Third, agents that influence hormone levels or otherwise modify the neuroendocrine system, such as nicotine, barbiturates, alcohol, opiates, and tetrahydrocannabinol, will be noted briefly to demonstrate the diversity of toxic agents that can influence neural development and affect personality, cognitive ability, and other aspects of behavior. 53 references.

  11. Adaptive Intuitionistic Fuzzy Enhancement of Brain Tumor MR Images.

    Science.gov (United States)

    Deng, He; Deng, Wankai; Sun, Xianping; Ye, Chaohui; Zhou, Xin

    2016-10-27

    Image enhancement techniques are able to improve the contrast and visual quality of magnetic resonance (MR) images. However, conventional methods cannot make up some deficiencies encountered by respective brain tumor MR imaging modes. In this paper, we propose an adaptive intuitionistic fuzzy sets-based scheme, called as AIFE, which takes information provided from different MR acquisitions and tries to enhance the normal and abnormal structural regions of the brain while displaying the enhanced results as a single image. The AIFE scheme firstly separates an input image into several sub images, then divides each sub image into object and background areas. After that, different novel fuzzification, hyperbolization and defuzzification operations are implemented on each object/background area, and finally an enhanced result is achieved via nonlinear fusion operators. The fuzzy implementations can be processed in parallel. Real data experiments demonstrate that the AIFE scheme is not only effectively useful to have information from images acquired with different MR sequences fused in a single image, but also has better enhancement performance when compared to conventional baseline algorithms. This indicates that the proposed AIFE scheme has potential for improving the detection and diagnosis of brain tumors.

  12. Incidental ferumoxytol artifacts in clinical brain MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bowser, Bruce A.; Campeau, Norbert G.; Carr, Carrie M.; Diehn, Felix E.; McDonald, Jennifer S.; Miller, Gary M.; Kaufmann, Timothy J. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

    2016-11-15

    Ferumoxytol (Feraheme) is a parenteral therapy approved for treatment of iron deficiency anemia. The product insert for ferumoxytol states that it may affect the diagnostic ability of MRI for up to 3 months. However, the expected effects may not be commonly recognized among clinical neuroradiologists. Our purpose is to describe the artifacts we have seen at our institution during routine clinical practice. We reviewed the patients at our institution that had brain MRI performed within 90 days of receiving intravenous ferumoxytol. The imaging was reviewed for specific findings, including diffusion-weighted imaging vascular susceptibility artifact, gradient-echo echo-planar T2*-weighted vascular susceptibility artifact, SWI/SWAN vascular susceptibility artifact, hypointense vascular signal on T2-weighted images, pre-gadolinium contrast vascular enhancement on magnetization-prepared rapid acquisition gradient echo (MPRAGE) imaging, and effects on post-gadolinium contrast T1 imaging. Multiple artifacts were observed in patients having a brain MRI within 3 days of receiving intravenous ferumoxytol. These included susceptibility artifact on DWI, GRE, and SWAN/SWI imaging, pre-gadolinium contrast increased vascular signal on MPRAGE imaging, and decreased expected enhancement on post-gadolinium contrast T1-weighted imaging. Ferumoxytol can create imaging artifacts which complicate clinical interpretation when brain MRI is performed within 3 days of administration. Recognition of the constellation of artifacts produced by ferumoxytol is important in order to obviate additional unnecessary examinations and mitigate errors in interpretation. (orig.)

  13. Adaptive Intuitionistic Fuzzy Enhancement of Brain Tumor MR Images

    Science.gov (United States)

    Deng, He; Deng, Wankai; Sun, Xianping; Ye, Chaohui; Zhou, Xin

    2016-10-01

    Image enhancement techniques are able to improve the contrast and visual quality of magnetic resonance (MR) images. However, conventional methods cannot make up some deficiencies encountered by respective brain tumor MR imaging modes. In this paper, we propose an adaptive intuitionistic fuzzy sets-based scheme, called as AIFE, which takes information provided from different MR acquisitions and tries to enhance the normal and abnormal structural regions of the brain while displaying the enhanced results as a single image. The AIFE scheme firstly separates an input image into several sub images, then divides each sub image into object and background areas. After that, different novel fuzzification, hyperbolization and defuzzification operations are implemented on each object/background area, and finally an enhanced result is achieved via nonlinear fusion operators. The fuzzy implementations can be processed in parallel. Real data experiments demonstrate that the AIFE scheme is not only effectively useful to have information from images acquired with different MR sequences fused in a single image, but also has better enhancement performance when compared to conventional baseline algorithms. This indicates that the proposed AIFE scheme has potential for improving the detection and diagnosis of brain tumors.

  14. Magnetic resonance imaging contrast enhancement of brain tumors at 3 tesla versus 1.5 tesla.

    Science.gov (United States)

    Nöbauer-Huhmann, Iris-Melanie; Ba-Ssalamah, Ahmed; Mlynarik, Vladimir; Barth, Markus; Schöggl, Alexander; Heimberger, Karl; Matula, Christian; Fog, Amura; Kaider, Alexandra; Trattnig, Siegfried

    2002-03-01

    To compare the diagnostic efficacy of a standard dose of MRI contrast agent in the evaluation of primary brain tumors and metastases using a high-field 3 tesla MR unit versus a 1.5 tesla MR unit. Sixteen patients with brain tumors were examined at both field strengths using identical axial T1-SE protocols pre- and postcontrast (0.1 mmol/kg gadolinium), and postcontrast coronal 3D GRE with magnetization preparation (MP-RAGE), which was adjusted separately for each field strength. Evaluation of the images was performed quantitatively and, in the case of T1-SE images, also by visual assessment. Tumor-to-brain-contrast after gadolinium administration using statistical evaluation of MP-RAGE scans was significantly higher at 3 tesla (97.5) than at 1.5 tesla (46.3). The same was true for T1-SE sequences (93.0 vs. 72.1). Signal enhancement of the lesions in T1-SE sequences was not significantly different between both field strengths. Administration of a gadolinium contrast agent produces higher contrast between tumor and normal brain at 3 tesla than at 1.5 tesla.

  15. Ultrasound contrast-agent improves imaging of lower limb occlusive disease

    DEFF Research Database (Denmark)

    Eiberg, J P; Hansen, M A; Jensen, F

    2003-01-01

    to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA)....

  16. Advanced MR brain imaging in preterm infants

    NARCIS (Netherlands)

    Bruine, Francisca Teresa de

    2013-01-01

    The aim of the thesis is to investigate the diagnostic value of MRI performed around term equivalent age in evaluating brain injury and predicting neurodevelopmental outcome at two years corrected age in very preterm infants with a gestational age of less than 32 weeks. MRI is a powerful tool to

  17. Ultrasound enhanced delivery of molecular imaging and therapeutic agents in Alzheimer's disease mouse models

    National Research Council Canada - National Science Library

    Raymond, Scott B; Treat, Lisa H; Dewey, Jonathan D; McDannold, Nathan J; Hynynen, Kullervo; Bacskai, Brian J

    2008-01-01

    .... Here we demonstrate that low-intensity focused ultrasound with a microbubble contrast agent may be used to transiently disrupt the blood-brain barrier, allowing non-invasive, localized delivery...

  18. Cross contrast multi-channel image registration using image synthesis for MR brain images.

    Science.gov (United States)

    Chen, Min; Carass, Aaron; Jog, Amod; Lee, Junghoon; Roy, Snehashis; Prince, Jerry L

    2017-02-01

    Multi-modal deformable registration is important for many medical image analysis tasks such as atlas alignment, image fusion, and distortion correction. Whereas a conventional method would register images with different modalities using modality independent features or information theoretic metrics such as mutual information, this paper presents a new framework that addresses the problem using a two-channel registration algorithm capable of using mono-modal similarity measures such as sum of squared differences or cross-correlation. To make it possible to use these same-modality measures, image synthesis is used to create proxy images for the opposite modality as well as intensity-normalized images from each of the two available images. The new deformable registration framework was evaluated by performing intra-subject deformation recovery, intra-subject boundary alignment, and inter-subject label transfer experiments using multi-contrast magnetic resonance brain imaging data. Three different multi-channel registration algorithms were evaluated, revealing that the framework is robust to the multi-channel deformable registration algorithm that is used. With a single exception, all results demonstrated improvements when compared against single channel registrations using the same algorithm with mutual information. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Use of automated image registration to generate mean brain SPECT image of Alzheimer`s patients

    Energy Technology Data Exchange (ETDEWEB)

    Imran, M.B.; Kawashima, Ryuta [Tohoku Univ., Sendai (Japan). Inst. of Development, Aging and Cancer; Awata, Shuichi [and others

    1998-06-01

    The purpose of this study was to compute and compare the group mean HMPAO brain SPECT images of patients with senile dementia of Alzheimer`s type (SDAT) and age matched control subjects after transformation of the individual images to a standard size and shape. Ten patients with Alzheimer`s disease (age 71.6{+-}5.0 yr) and ten age matched normal subjects (age 71.0{+-}6.1 yr) participated in this study. Tc-99m HMPAO brain SPECT and X-ray CT scans were acquired for each subject. SPECT images were normalized to an average activity of 100 counts/pixel. Individual brain images were transformed to a standard size and shape with the help of Automated Image Registration (AIR). Realigned brain SPECT images of both groups were used to generate mean and standard deviation images by arithmetic operations on voxel based numerical values. Mean images of both groups were compared by applying the unpaired t-test on a voxel by voxel basis to generate three dimensional T-maps. X-ray CT images of individual subjects were evaluated by means of a computer program for brain atrophy. A significant decrease in relative radioisotope (RI) uptake was present in the bilateral superior and inferior parietal lobules (p<0.05), bilateral inferior temporal gyri, and the bilateral superior and middle frontal gyri (p<0.001). The mean brain atrophy indices for patients and normal subjects were 0.853{+-}0.042 and 0.933{+-}0.017 respectively, the difference being statistically significant (p<0.001). The use of a brain image standardization procedure increases the accuracy of voxel based group comparisons. Thus, intersubject averaging enhances the capacity for detection of abnormalities in functional brain images by minimizing the influence of individual variation. (author)

  20. Evans blue dye-enhanced imaging of the brain microvessels using spectral focusing coherent anti-Stokes Raman scattering microscopy.

    Directory of Open Access Journals (Sweden)

    Bo-Ram Lee

    Full Text Available We performed dye-enhanced imaging of mouse brain microvessels using spectral focusing coherent anti-Stokes Raman scattering (SF-CARS microscopy. The resonant signals from C-H stretching in forward CARS usually show high background intensity in tissues, which makes CARS imaging of microvessels difficult. In this study, epi-detection of back-scattered SF-CARS signals showed a negligible background, but the overall intensity of resonant CARS signals was too low to observe the network of brain microvessels. Therefore, Evans blue (EB dye was used as contrasting agent to enhance the back-scattered SF-CARS signals. Breakdown of brain microvessels by inducing hemorrhage in a mouse was clearly visualized using backward SF-CARS signals, following intravenous injection of EB. The improved visualization of brain microvessels with EB enhanced the sensitivity of SF-CARS, detecting not only the blood vessels themselves but their integrity as well in the brain vasculature.

  1. Brain magnetic resonance imaging in adults with asthma.

    Science.gov (United States)

    Parker, J; Wolansky, L J; Khatry, D; Geba, G P; Molfino, N A

    2011-01-01

    In individuals with asthma, potential central nervous system changes can occur as a consequence of their asthma or therapy. Clinical trials of anti-asthmatic therapies might benefit from using magnetic resonance imaging (MRI) to assess potential brain abnormalities. As part of the clinical safety evaluation of a monoclonal antibody directed against interleukin-9 for the treatment of asthma, we assessed whether brain MRI is an appropriate screening tool to evaluate potential neurotoxicity. Brain MRIs were conducted as part of a prespecified safety evaluation in adults aged 19 to 47 years with mild to moderate asthma treated with either the investigational monoclonal antibody or placebo. An independent neuroradiologist performed a blinded review of brain MRI scans obtained at baseline before dosing and day 28 after dosing from two separate clinical studies. Fifteen brain MRI abnormalities were noted in 13 of 21 subjects with asthma (62%). Nonspecific deep white matter hyperintensities (24%), perivascular space (24%), and abnormal anatomic findings (14%) were noted either at baseline or follow-up. Only 8 of 21 subjects (38%) with asthma had normal brain MRI results. The high rate of incidental brain MRI findings suggests that these abnormalities are relatively common in patients with asthma. Thus, brain MRI may not be an appropriate screening tool to evaluate potential neurotoxicity in subjects during routine clinical studies without a baseline examination. Due to artifacts simulating lesions, an experienced radiologist should interpret all brain MRI results. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Double-echo perfusion-weighted MR imaging: basic concepts and application in brain tumors for the assessment of tumor blood volume and vascular permeability.

    Science.gov (United States)

    Uematsu, Hidemasa; Maeda, Masayuki

    2006-01-01

    Perfusion-weighted magnetic resonance (MR) imaging using contrast agents plays a key role in characterizing tumors of the brain. We have shown that double-echo perfusion-weighted MR imaging (DEPWI) is potentially useful in assessing brain tumors. Quantitative indices, such as tumor blood volume, are obtained using DEPWI, which allows correction of underestimation of tumor blood volume due to leakage of contrast agents from tumor vessels, in addition to simultaneous acquisition of tumor vessel permeability. This article describes basic concepts of DEPWI and demonstrates clinical applications in brain tumors.

  3. Segmentation of Striatal Brain Structures from High Resolution PET Images

    Directory of Open Access Journals (Sweden)

    Ricardo J. P. C. Farinha

    2009-01-01

    Full Text Available We propose and evaluate an automatic segmentation method for extracting striatal brain structures (caudate, putamen, and ventral striatum from parametric C11-raclopride positron emission tomography (PET brain images. We focus on the images acquired using a novel brain dedicated high-resolution (HRRT PET scanner. The segmentation method first extracts the striatum using a deformable surface model and then divides the striatum into its substructures based on a graph partitioning algorithm. The weighted kernel k-means algorithm is used to partition the graph describing the voxel affinities within the striatum into the desired number of clusters. The method was experimentally validated with synthetic and real image data. The experiments showed that our method was able to automatically extract caudate, ventral striatum, and putamen from the images. Moreover, the putamen could be subdivided into anterior and posterior parts. An automatic method for the extraction of striatal structures from high-resolution PET images allows for inexpensive and reproducible extraction of the quantitative information from these images necessary in brain research and drug development.

  4. Brain magnetic resonance imaging of infants exposed prenatally to buprenorphine

    Energy Technology Data Exchange (ETDEWEB)

    Kahila, H.; Kivitie-Kallio, S.; Halmesmaki, E.; Valanne, L.; Autti, T. [Dept. of Obstetrics and Gynecology, Dept. of Pediatrics, and Helsinki Medical Imaging Center, Helsinki Univ. Central Hospital (Finland)

    2007-02-15

    Purpose: To evaluate the brains of newborns exposed to buprenorphine prenatally. Material and Methods: Seven neonates followed up antenatally in connection with their mothers' buprenorphine replacement therapy underwent 1.5T magnetic resonance imaging (MRI) of the brain before the age of 2 months. The infants were born to heavy drug abusers. Four mothers were hepatitis C positive, and all were HIV negative. All mothers smoked tobacco and used benzodiazepines. All pregnancies were full term, and no perinatal asphyxia occurred. All but one neonate had abstinence syndrome and needed morphine replacement therapy. Results: Neither structural abnormalities nor abnormalities in signal intensity were recorded. Conclusion: Buprenorphine replacement therapy does not seem to cause any major structural abnormalities of the brain, and it may prevent known hypoxic-ischemic brain changes resulting from uncontrolled drug abuse. Longitudinal studies are needed to assess possible abnormalities in the brain maturation process.

  5. Normal feline brain: clinical anatomy using magnetic resonance imaging.

    Science.gov (United States)

    Mogicato, G; Conchou, F; Layssol-Lamour, C; Raharison, F; Sautet, J

    2012-04-01

    The purpose of this study was to provide a clinical anatomy atlas of the feline brain using magnetic resonance imaging (MRI). Brains of twelve normal cats were imaged using a 1.5 T magnetic resonance unit and an inversion/recovery sequence (T1). Fourteen relevant MRI sections were chosen in transverse, dorsal, median and sagittal planes. Anatomic structures were identified and labelled using anatomical texts and Nomina Anatomica Veterinaria, sectioned specimen heads, and previously published articles. The MRI sections were stained according to the major embryological and anatomical subdivisions of the brain. The relevant anatomical structures seen on MRI will assist clinicians to better understand MR images and to relate this neuro-anatomy to clinical signs. © 2011 Blackwell Verlag GmbH.

  6. Mapping fetal brain development in utero using magnetic resonance imaging: the Big Bang of brain mapping.

    Science.gov (United States)

    Studholme, Colin

    2011-08-15

    The development of tools to construct and investigate probabilistic maps of the adult human brain from magnetic resonance imaging (MRI) has led to advances in both basic neuroscience and clinical diagnosis. These tools are increasingly being applied to brain development in adolescence and childhood, and even to neonatal and premature neonatal imaging. Even earlier in development, parallel advances in clinical fetal MRI have led to its growing use as a tool in challenging medical conditions. This has motivated new engineering developments encompassing optimal fast MRI scans and techniques derived from computer vision, the combination of which allows full 3D imaging of the moving fetal brain in utero without sedation. These promise to provide a new and unprecedented window into early human brain growth. This article reviews the developments that have led us to this point, examines the current state of the art in the fields of fast fetal imaging and motion correction, and describes the tools to analyze dynamically changing fetal brain structure. New methods to deal with developmental tissue segmentation and the construction of spatiotemporal atlases are examined, together with techniques to map fetal brain growth patterns.

  7. Imaging Monoamine Oxidase in the Human Brain

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J. S.; Volkow, N. D.; Wang, G-J.; Logan, Jean

    1999-11-10

    Positron emission tomography (PET) studies mapping monoamine oxidase in the human brain have been used to measure the turnover rate for MAO B; to determine the minimum effective dose of a new MAO inhibitor drug lazabemide and to document MAO inhibition by cigarette smoke. These studies illustrate the power of PET and radiotracer chemistry to measure normal biochemical processes and to provide information on the effect of drug exposure on specific molecular targets.

  8. Effect of glucose level on brain FDG-PET images

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Young; Lee, Yong Ki; Ahn, Sung Min [Dept. of Radiological Science, Gachon University, Seongnam (Korea, Republic of)

    2017-06-15

    In addition to tumors, normal tissues, such as the brain and myocardium can intake {sup 18}F-FDG, and the amount of {sup 18}F-FDG intake by normal tissues can be altered by the surrounding environment. Therefore, a process is necessary during which the contrasts of the tumor and normal tissues can be enhanced. Thus, this study examines the effects of glucose levels on FDG PET images of brain tissues, which features high glucose activity at all times, in small animals. Micro PET scan was performed on fourteen mice after injecting {sup 18}F-FDG. The images were compared in relation to fasting. The findings showed that the mean SUV value w as 0 .84 higher in fasted mice than in non-fasted mice. During observation, the images from non-fasted mice showed high accumulation in organs other than the brain with increased surrounding noise. In addition, compared to the non-fasted mice, the fasted mice showed higher early intake and curve increase. The findings of this study suggest that fasting is important in assessing brain functions in brain PET using {sup 18}F-FDG. Additional studies to investigate whether caffeine levels and other preprocessing items have an impact on the acquired images would contribute to reducing radiation exposure in patients.

  9. Hybrid PET/MR Imaging and Brain Connectivity.

    Science.gov (United States)

    Aiello, Marco; Cavaliere, Carlo; Salvatore, Marco

    2016-01-01

    In recent years, brain connectivity is gaining ever-increasing interest from the interdisciplinary research community. The study of brain connectivity is characterized by a multifaceted approach providing both structural and functional evidence of the relationship between cerebral regions at different scales. Although magnetic resonance (MR) is the most established imaging modality for investigating connectivity in vivo, the recent advent of hybrid positron emission tomography (PET)/MR scanners paved the way for more comprehensive investigation of brain organization and physiology. Due to the high sensitivity and biochemical specificity of radiotracers, combining MR with PET imaging may enrich our ability to investigate connectivity by introducing the concept of metabolic connectivity and cometomics and promoting new insights on the physiological and molecular bases underlying high-level neural organization. This review aims to describe and summarize the main methods of analysis of brain connectivity employed in MR imaging and nuclear medicine. Moreover, it will discuss practical aspects and state-of-the-art techniques for exploiting hybrid PET/MR imaging to investigate the relationship of physiological processes and brain connectivity.

  10. Hybrid PET/MR Imaging and Brain Connectivity

    Directory of Open Access Journals (Sweden)

    Marco eAiello

    2016-03-01

    Full Text Available In recent years, brain connectivity is gaining ever-increasing interest from the interdisciplinary research community. The study of brain connectivity is characterized by a multifaceted approach providing both structural and functional evidence of the relationship between cerebral regions at different scales. Although magnetic resonance (MR is the most established imaging modality for investigating connectivity in vivo, the recent advent of hybrid positron emission tomography (PET/MR scanners paved the way for more comprehensive investigation of brain organization and physiology. Due to the high sensitivity and biochemical specificity of radiotracers, combining MR with PET imaging may enrich our ability to investigate connectivity by introducing the concept of metabolic connectivity and cometomics and promoting new insights on the physiological and molecular bases underlying high-level neural organization. This review aims to describe and summarize the main methods of analysis of brain connectivity employed in MR imaging and nuclear medicine. Moreover, it will discuss practical aspects and state-of-the-art techniques for exploiting hybrid PET/MR imaging to investigate the relationship of physiological processes and brain connectivity.

  11. RF inhomogeneity compensation in structural brain imaging

    National Research Council Canada - National Science Library

    Deichmann, R; Good, C.D; Turner, R

    2002-01-01

    .... It is shown experimentally that images acquired with the compensation pulse may be segmented without using intensity correction algorithms during data postprocessing. Magn Reson Med 47:398–402, 2002. © 2002 Wiley‐Liss, Inc.

  12. Radioiodinated carnitine and acylcarnitine analogs as potential myocardial imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, D.S.

    1991-01-01

    R-carnitine is extremely important in mammalian energy metabolism. Gamma-butyrobetaine, the immediate biosynthetic precursor to R-carnitine, is synthesized in many organs. However, only liver can hydroxylate gamma-butyrobetaine to carnitine. Thus the transport of carnitine from its site of synthesis to the site of utilization is of utmost importance. Carnitine is found in highest concentration in cardiac and skeletal muscle, where it is required for the transport of fatty acids into the mitochondria. Before fatty acids are utilized as fuel for the myocyte by beta-oxidation, they are bound to carnitine as an acylcarnitine ester at the 3-hydroxyl, and transported across the micochondrial membranes. R,S-Carnitine has been shown to be taken up by myocytes. The author has begun a study on the use of carnitine derivatives as potential carriers for the site-specific delivery of radioiodine to bidning sites in the myocardium. Such agents labeled with a gamma-emitting nuclide such as iodine-123 would be useful for the noninvasive imaging of these tissues. The aim was to synthesize a variety of radiolabeled analogs of carnitine and acylcarnitine to address questions of transport, binding and availability for myocardial metabolism. These analogs consist of N-alkylated derivatives of carnitine, acylcarnitine esters as well as carnitine amides and ethers. One C-alkylated derivative showed interesting biodistribution, elevated myocardial uptake and competition with carnitine for binding in the myocardium.

  13. Development of Iron Doped Silicon Nanoparticles as Bimodal Imaging Agents

    Science.gov (United States)

    Singh, Mani P.; Atkins, Tonya M.; Muthuswamy, Elayaraja; Kamali, Saeed; Tu, Chuqiao; Louie, Angelique Y.; Kauzlarich, Susan M.

    2012-01-01

    We demonstrate the synthesis of water-soluble allylamine terminated Fe doped Si (SixFe) nanoparticles as bimodal agents for optical and magnetic imaging. The preparation involves the synthesis of a single source iron containing precursor, Na4Si4 with x% Fe (x = 1, 5, 10), and its subsequent reaction with NH4Br to produce hydrogen terminated SixFe nanoparticles. The hydrogen-capped nanoparticles are further terminated with allylamine via thermal hydrosilylation. Transmission electron microscopy (TEM) indicates that the average particle diameter is ~3.0±1.0 nm. The Si5Fe nanoparticles show strong photoluminescence quantum yield in water (~ 10 %) with significant T2 contrast (r2/r1value of 4.31). Electron paramagnetic resonance (EPR) and Mössbauer spectroscopies indicate that iron in the nanoparticles is in the +3 oxidation state. Analysis of cytotoxicity using the resazurin assay on HepG2 liver cells indicates that the particles have minimal toxicity. PMID:22616623

  14. An agent harms a victim: A functional magnetic resonance imaging study on specific moral emotions

    Energy Technology Data Exchange (ETDEWEB)

    Kedia, G. [INSERM, Inst Hlth et Med Res, U797, Res Unit Neuroimaging Psychiat, F-91401 Orsay (France); Kedia, G.; Martinot, J.L. [CEA, DSV, I2BM, SHFJ, Orsay (France); Kedia, G.; Martinot, J.L. [Univ Paris Sud, U797, Paris (France); Kedia, G.; Hilton, D. [Univ Toulouse, Toulouse (France); Berthoz, S. [Paris Descartes Univ, U797, Paris (France); Wessa, M. [Univ Heidelber, Cent Inst Mental Hlth, D-6800 Mannheim (Germany)

    2008-07-01

    The statement 'An agent harms a victim' depicts a situation that triggers moral emotions. Depending on whether the agent and the victim are the self or someone else, it can lead to four different moral emotions: self-anger ('I harm myself'), guilt ('I harm someone'), other-anger ('someone harms me'), and compassion ('someone harms someone'). In order to investigate the neural correlates of these emotions, we examined brain activation patterns elicited by variations in the agent (self vs. other) and the victim (self vs. other) of a harmful action. Twenty-nine healthy participants underwent functional magnetic resonance imaging while imagining being in situations in which they or someone else harmed themselves or someone else. Results indicated that the three emotional conditions associated with the involvement of other, either as agent or victim (guilt, other-anger, and compassion conditions), all activated structures that have been previously associated with the Theory of Mind (ToM, the attribution of mental states to others), namely, the dorsal medial prefrontal cortex, the precuneus, and the bilateral temporo-parietal junction. Moreover, the two conditions in which both the self and other were concerned by the harmful action (guilt and other-anger conditions) recruited emotional structures (i. e., the bilateral amygdala, anterior cingulate, and basal ganglia). These results suggest that specific moral emotions induce different neural activity depending on the extent to which they involve the self and other. (authors)

  15. Registration of challenging pre-clinical brain images

    Science.gov (United States)

    Crum, William R.; Modo, Michel; Vernon, Anthony C.; Barker, Gareth J.; Williams, Steven C.R.

    2013-01-01

    The size and complexity of brain imaging studies in pre-clinical populations are increasing, and automated image analysis pipelines are urgently required. Pre-clinical populations can be subjected to controlled interventions (e.g., targeted lesions), which significantly change the appearance of the brain obtained by imaging. Existing systems for registration (the systematic alignment of scans into a consistent anatomical coordinate system), which assume image similarity to a reference scan, may fail when applied to these images. However, affine registration is a particularly vital pre-processing step for subsequent image analysis which is assumed to be an effective procedure in recent literature describing sophisticated techniques such as manifold learning. Therefore, in this paper, we present an affine registration solution that uses a graphical model of a population to decompose difficult pairwise registrations into a composition of steps using other members of the population. We developed this methodology in the context of a pre-clinical model of stroke in which large, variable hyper-intense lesions significantly impact registration performance. We tested this technique systematically in a simulated human population of brain tumour images before applying it to pre-clinical models of Parkinson's disease and stroke. PMID:23558335

  16. BRAIN IMAGING IN THE STUDY OF ALZHEIMER'S DISEASE

    Science.gov (United States)

    Reiman, Eric M.; Jagust, William J.

    2012-01-01

    Over the last 20 years, there has been extraordinary progress in brain imaging research and its application to the study of Alzheimer's disease (AD). Brain imaging researchers have contributed to the scientific understanding, early detection and tracking of AD. They have set the stage for imaging techniques to play growing roles in the clinical setting, the evaluation of disease-modifying treatments, and the identification of demonstrably effective prevention therapies. They have developed ground-breaking methods, including positron emission tomography (PET) ligands to measure fibrillar amyloid-β (Aβ) deposition, new magnetic resonance imaging (MRI) pulse sequences, and powerful image analysis techniques, to help in these endeavors. Additional work is needed to develop even more powerful imaging methods, to further clarify the relationship and time course of Aβ and other disease processes in the predisposition to AD, to establish the role of brain imaging methods in the clinical setting, and to provide the scientific means and regulatory approval pathway needed to evaluate the range of promising disease-modifying and prevention therapies as quickly as possible. Twenty years from now, AD may not yet be a distant memory, but the best is yet to come. PMID:22173295

  17. Effects of the nootropic agents adafenoxate and meclofenoxate on brain biogenic monoamines in aged rats.

    Science.gov (United States)

    Stancheva, S L; Petkov, V D; Petkov, V V

    1988-01-01

    The effect of the nootropic agents meclofenoxate (Mf) and adafenoxate (Adf) on the content of biogenic monoamines in the frontal cerebral cortex, striatum, hypothalamus, and hippocampus of 22-month-old rats was studied. Mf and Adf were administered orally for seven days twice daily in a dose of 50 mg/kg weight. Both agents tested increased the content of serotonin (5-HT) in the cortex and striatum. Adf also raised the noradrenaline (NA) content in the cortex and hippocampus, lowering the dopamine (DA) level in the striatum. Comparison of the results obtained in the present study with the finding of earlier experiments of ours on 4-5-month-old rats revealed the following: 1. Biogenic monoamines (BMA) in the brain tend to decrease with ageing. 2. In addition to the unidirectional effects of Mf and Adf on the BMA content in the brain of both young and old rats, but in some cases there were also differences. 3. The comparison of the effects of Mf and Adf on the BMA content in the different brain regions with the changes in this content, characteristic of certain diseases, reveals prospects for selectivity in the application of these nootropic agents, which are generally rather similar in pharmacological characteristics.

  18. Functional photoacoustic tomography for neonatal brain imaging: developments and challenges

    Science.gov (United States)

    Hariri, Ali; Tavakoli, Emytis; Adabi, Saba; Gelovani, Juri; Avanaki, Mohammad R. N.

    2017-03-01

    Transfontanelle ultrasound imaging (TFUSI) is a routine diagnostic brain imaging method in infants who are born prematurely, whose skull bones have not completely fused together and have openings between them, so-called fontanelles. Open fontanelles in neonates provide acoustic windows, allowing the ultrasound beam to freely pass through. TFUSI is used to rule out neurological complications of premature birth including subarachnoid hemorrhage (SAH), intraventricular (IVH), subependimal (SEPH), subdural (SDH) or intracerebral (ICH) hemorrhages, as well as hypoxic brain injuries. TFUSI is widely used in the clinic owing to its low cost, safety, accessibility, and noninvasive nature. Nevertheless, the accuracy of TFUSI is limited. To address several limitations of current clinical imaging modalities, we develop a novel transfontanelle photoacoustic imaging (TFPAI) probe, which, for the first time, should allow for non-invasive structural and functional imaging of the infant brain. In this study, we test the feasibility of TFPAI for detection of experimentally-induced intra ventricular and Intraparenchymal hemorrhage phantoms in a sheep model with a surgically-induced cranial window which will serve as a model of neonatal fontanelle. This study is towards using the probe we develop for bedside monitoring of neonates with various disease conditions and complications affecting brain perfusion and oxygenation, including apnea, asphyxia, as well as for detection of various types of intracranial hemorrhages (SAH, IVH, SEPH, SDH, ICH).

  19. Synchrotron radiation imaging is a powerful tool to image brain microvasculature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Mengqi; Sun, Danni; Xie, Yuanyuan; Xia, Jian; Long, Hongyu; Hu, Kai; Xiao, Bo, E-mail: csuxiaobo123456@163.com [Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Peng, Guanyun [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2014-03-15

    Synchrotron radiation (SR) imaging is a powerful experimental tool for micrometer-scale imaging of microcirculation in vivo. This review discusses recent methodological advances and findings from morphological investigations of cerebral vascular networks during several neurovascular pathologies. In particular, it describes recent developments in SR microangiography for real-time assessment of the brain microvasculature under various pathological conditions in small animal models. It also covers studies that employed SR-based phase-contrast imaging to acquire 3D brain images and provide detailed maps of brain vasculature. In addition, a brief introduction of SR technology and current limitations of SR sources are described in this review. In the near future, SR imaging could transform into a common and informative imaging modality to resolve subtle details of cerebrovascular function.

  20. Brain Volume Estimation Enhancement by Morphological Image Processing Tools

    Directory of Open Access Journals (Sweden)

    Zeinali R.

    2017-12-01

    Full Text Available Background: Volume estimation of brain is important for many neurological applications. It is necessary in measuring brain growth and changes in brain in normal/ abnormal patients. Thus, accurate brain volume measurement is very important. Magnetic resonance imaging (MRI is the method of choice for volume quantification due to excellent levels of image resolution and between-tissue contrast. Stereology method is a good method for estimating volume but it requires to segment enough MRI slices and have a good resolution. In this study, it is desired to enhance stereology method for volume estimation of brain using less MRI slices with less resolution. Methods: In this study, a program for calculating volume using stereology method has been introduced. After morphologic method, dilation was applied and the stereology method enhanced. For the evaluation of this method, we used T1-wighted MR images from digital phantom in BrainWeb which had ground truth. Results: The volume of 20 normal brain extracted from BrainWeb, was calculated. The volumes of white matter, gray matter and cerebrospinal fluid with given dimension were estimated correctly. Volume calculation from Stereology method in different cases was made. In three cases, Root Mean Square Error (RMSE was measured. Case I with T=5, d=5, Case II with T=10, D=10 and Case III with T=20, d=20 (T=slice thickness, d=resolution as stereology parameters. By comparing these results of two methods, it is obvious that RMSE values for our proposed method are smaller than Stereology method. Conclusion: Using morphological operation, dilation allows to enhance the estimation volume method, Stereology. In the case with less MRI slices and less test points, this method works much better compared to Stereology method.

  1. Lessons Learned from MAVRIC's Brain: An Anticipatory Artificial Agent and Proto-consciousness

    Science.gov (United States)

    Mobus, George

    2002-09-01

    MAVRIC II is a mobile, autonomous robot whose brain is comprised almost entirely of artificial adaptrode-based neurons. These neurons were previously shown to encode anticipatory actions. The architecture of this brain is based on the Extended Braitenberg Architecture (EBA). We are still in the process of collecting hard data on the behavioral traits of MAVRIC in the generalized foraging search task. But even now sufficient qualitative aspects of MAVRIC's behavior have been garnered from foraging experiments to lend strong support to the theory that MAVRIC is a highly adaptive, life-like agent. The development of the current MAVRIC brain has led to some important insights into the nature of intelligent control. In this paper we elucidate some of these principles in the form of lessons learned, and project the potential for future developments.

  2. The imaging of HIV-related brain disease : clinical: imaging

    African Journals Online (AJOL)

    Furthermore, a correlation between declining cognitive function and the loss of ... and highly active antiretroviral therapy (HAART) is an important aspect of managing these conditions effec- tively.2 In ... sult in damage to white matter tracts in the brain.6 Once damage is established and related cognitive disorders ensue, the ...

  3. Imaging of Brain Tumors with Copper-64 Chloride: Early Experience and Results.

    Science.gov (United States)

    Panichelli, Paola; Villano, Carlo; Cistaro, Angelina; Bruno, Andrea; Barbato, Francesco; Piccardo, Arnoldo; Duatti, Adriano

    2016-06-01

    To conduct the first investigational study that is aimed at evaluating the ability of the simple salt (64)CuCl2 to diagnose cerebral tumors in patients affected by glioblastoma multiforme (GBM). Nineteen patients with a documented history and radiologic evidence of brain tumors were enrolled in the study. Eighteen patients were diagnosed with GBM, and one patient was diagnosed with grade II astrocytoma. After initial cerebral magnetic resonance imaging (MRI), patients were administered with (64)CuCl2 (13 MBq/kg) and brain positron emission tomography (PET)/computed tomography (CT) imaging was performed at 1, 3, and 24 hours after administration. Standardized uptake values (SUVs) were calculated and used to figure out the pharmacokinetic profile of the tracer. Absorbed radiation doses were estimated using OLINDA/EXM. Copper-64 chloride clearly visualized brain cancerous lesions within 1 hour after injection, with stable retention of radioactivity at 3 and 24 hours. Excellent agreement was found between PET/CT and MRI. No uptake of the tracer was observed in low-grade astrocytoma. The agent cleared rapidly from the blood and was mostly excreted through the liver, without significant kidney washout. Analysis of time variation of SUVmax values showed persistent uptake in malignant tissues with a slight increase of radioactive concentration at 24 hours. Copper-64 chloride has favorable biological properties for brain imaging and warrants further investigation as a diagnostic tracer for GBM.

  4. Ultrasound contrast-agent improves imaging of lower limb occlusive disease

    DEFF Research Database (Denmark)

    Eiberg, J P; Hansen, M A; Jensen, F

    2003-01-01

    to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA).......to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA)....

  5. Congenital heart disease: cardiovascular MR imaging by using an intravascular blood pool contrast agent.

    NARCIS (Netherlands)

    Makowski, M.R.; Wiethoff, A.J.; Uribe, S.; Parish, V.; Botnar, R.M.; Bell, A.; Kiesewetter, C.; Beerbaum, P.B.J.; Jansen, C.H.; Razavi, R.; Schaeffter, T.; Greil, G.F.

    2011-01-01

    PURPOSE: To compare the image quality and diagnostic performance of a contrast agent-specific inversion-recovery (IR) steady-state free precession (SSFP) magnetic resonance (MR) imaging sequence performed by using an intravascular contrast agent (gadofosveset trisodium) with those of a commonly used

  6. Structural Image Analysis of the Brain in Neuropsychology Using Magnetic Resonance Imaging (MRI) Techniques.

    Science.gov (United States)

    Bigler, Erin D

    2015-09-01

    Magnetic resonance imaging (MRI) of the brain provides exceptional image quality for visualization and neuroanatomical classification of brain structure. A variety of image analysis techniques provide both qualitative as well as quantitative methods to relate brain structure with neuropsychological outcome and are reviewed herein. Of particular importance are more automated methods that permit analysis of a broad spectrum of anatomical measures including volume, thickness and shape. The challenge for neuropsychology is which metric to use, for which disorder and the timing of when image analysis methods are applied to assess brain structure and pathology. A basic overview is provided as to the anatomical and pathoanatomical relations of different MRI sequences in assessing normal and abnormal findings. Some interpretive guidelines are offered including factors related to similarity and symmetry of typical brain development along with size-normalcy features of brain anatomy related to function. The review concludes with a detailed example of various quantitative techniques applied to analyzing brain structure for neuropsychological outcome studies in traumatic brain injury.

  7. Adaptive optical microscope for brain imaging in vivo

    Science.gov (United States)

    Wang, Kai

    2017-04-01

    The optical heterogeneity of biological tissue imposes a major limitation to acquire detailed structural and functional information deep in the biological specimens using conventional microscopes. To restore optimal imaging performance, we developed an adaptive optical microscope based on direct wavefront sensing technique. This microscope can reliably measure and correct biological samples induced aberration. We demonstrated its performance and application in structural and functional brain imaging in various animal models, including fruit fly, zebrafish and mouse.

  8. Multi-stimuli responsive Cu2S nanocrystals as trimodal imaging and synergistic chemo-photothermal therapy agents

    Science.gov (United States)

    Poulose, Aby Cheruvathoor; Veeranarayanan, Srivani; Mohamed, M. Sheikh; Nagaoka, Yutaka; Romero Aburto, Rebeca; Mitcham, Trevor; Ajayan, Pulickel M.; Bouchard, Richard R.; Sakamoto, Yasushi; Yoshida, Yasuhiko; Maekawa, Toru; Sakthi Kumar, D.

    2015-04-01

    A size and shape tuned, multifunctional metal chalcogenide, Cu2S-based nanotheranostic agent is developed for trimodal imaging and multimodal therapeutics against brain cancer cells. This theranostic agent was highly efficient in optical, photoacoustic and X-ray contrast imaging systems. The folate targeted NIR-responsive photothermal ablation in synergism with the chemotherapeutic action of doxorubicin proved to be a rapid precision guided cancer-killing module. The multi-stimuli, i.e., pH-, thermo- and photo-responsive drug release behavior of the nanoconjugates opens up a wider corridor for on-demand triggered drug administration. The simple synthesis protocol, combined with the multitudes of interesting features packed into a single nanoformulation, clearly demonstrates the competing role of this Cu2S nanosystem in future cancer treatment strategies.A size and shape tuned, multifunctional metal chalcogenide, Cu2S-based nanotheranostic agent is developed for trimodal imaging and multimodal therapeutics against brain cancer cells. This theranostic agent was highly efficient in optical, photoacoustic and X-ray contrast imaging systems. The folate targeted NIR-responsive photothermal ablation in synergism with the chemotherapeutic action of doxorubicin proved to be a rapid precision guided cancer-killing module. The multi-stimuli, i.e., pH-, thermo- and photo-responsive drug release behavior of the nanoconjugates opens up a wider corridor for on-demand triggered drug administration. The simple synthesis protocol, combined with the multitudes of interesting features packed into a single nanoformulation, clearly demonstrates the competing role of this Cu2S nanosystem in future cancer treatment strategies. Electronic supplementary information (ESI) available: Methodology and additional experimental results. See DOI: 10.1039/c4nr07139e

  9. Brain imaging of pain: state of the art

    Directory of Open Access Journals (Sweden)

    Morton DL

    2016-09-01

    Full Text Available Debbie L Morton, Javin S Sandhu, Anthony KP Jones Human Pain Research Group, Institute of Brain, Behaviour and Mental Health, University of Manchester, Manchester, UK Abstract: Pain is a complex sensory and emotional experience that is heavily influenced by prior experience and expectations of pain. Before the development of noninvasive human brain imaging, our grasp of the brain’s role in pain processing was limited to data from postmortem studies, direct recording of brain activity, patient experience and stimulation during neurosurgical procedures, and animal models of pain. Advances made in neuroimaging have bridged the gap between brain activity and the subjective experience of pain and allowed us to better understand the changes in the brain that are associated with both acute and chronic pain. Additionally, cognitive influences on pain such as attention, anticipation, and fear can now be directly observed, allowing for the interpretation of the neural basis of the psychological modulation of pain. The use of functional brain imaging to measure changes in endogenous neurochemistry has increased our understanding of how states of increased resilience and vulnerability to pain are maintained. Keywords: fMRI, PET, EEG, arthritis, fibromyalgia

  10. Magnetic Resonance Imaging (MRI Contrast Agents for Tumor Diagnosis

    Directory of Open Access Journals (Sweden)

    Weiren Cheng

    2013-01-01

    Full Text Available This review focuses on MRI contrast agents for tumor diagnosis. Several types of low molecular weight Gd3+-based complexes and dextran-coated superparamagnetic iron oxide (SPIO nanoparticles have been used for clinical tumor diagnosis as longitudinal relaxation time (T1 and transverse relaxation time (T2 MRI contrast agents, respectively. To further improve the sensitivity of MRI, new types of chelates for T1 MRI contrast agents and combination of low molecular weight T1 MRI contrast agents with different types of carriers have been investigated. Different types of materials for forming secure coating layers of SPIO and novel superparamagnetic particles with higher relaxivity values have been explored. Various types of ligands were applied to improve the capability to target tumor for both T1 and T2 contrast agents. Furthermore, MRI contrast agents for detection of tumor metabolism were also pursued.

  11. Brain imaging and the effects of caffeine and nicotine.

    Science.gov (United States)

    Dager, S R; Friedman, S D

    2000-12-01

    Caffeine and nicotine are the most common psychostimulant drugs used worldwide. Structural neuroimaging findings associated with caffeine and nicotine consumption are limited and primarily reflect the putative relationship between smoking and white matter hyperintensities (WMH), a finding that warrants further appraisal of its clinical implications. The application of newer brain imaging modalities that measure subtle haemodynamic changes or tissue-based chemistry in order to better elucidate brain functional processes, including mechanisms underlying addiction to nicotine and caffeine and the brain functional consequences, provide intriguing findings. Potential influences of caffeine and nicotine on the functional contrast, or metabolic response, to neural activation also necessitates the careful appraisal of the effects that these commonly used drugs may have on the results of functional imaging.

  12. Brain imaging in myotonic dystrophy type 1: A systematic review

    NARCIS (Netherlands)

    Okkersen, K.; Monckton, D.G.; Le, N.; Tuladhar, A.M.; Raaphorst, J.; Engelen, B.G.M. van

    2017-01-01

    OBJECTIVE: To systematically review brain imaging studies in myotonic dystrophy type 1 (DM1). METHODS: We searched Embase (index period 1974-2016) and MEDLINE (index period 1946-2016) for studies in patients with DM1 using MRI, magnetic resonance spectroscopy (MRS), functional MRI (fMRI), CT,

  13. Brain imaging in patients with freezing of gait

    NARCIS (Netherlands)

    Bartels, Anna L.; Leenders, Klaus L.

    2008-01-01

    Freezing of gait (FOG) is a disabling gait disturbance with unknown cerebral pathophysiology. In this review, we discuss the functional brain imaging Studies that address gait physiology and pathophysiology of FOG. Radiotracer metabolic studies show basal ganglia-cortical circuitry involvement in

  14. Reliability and Accuracy of Brain Volume Measurement on MR Imaging

    DEFF Research Database (Denmark)

    Yamagchii, Kechiro; Lassen, Anders; Ring, Poul

    1998-01-01

    Yamaguchi, K., Lassen, A. And Ring, P. Reliability and Accuracy of Brain Volume Measurement on MR Imaging. Abstract at ESMRMB98 European Society for Magnetic Resonance in Medicine and Biology, Geneva, Sept 17-20, 1998 Danish Research Center for Magnetic Resonance, Hvidovre University Hospital...

  15. Brain connectomics imaging in schizophrenia study

    Science.gov (United States)

    Tseng, Wen-Yih Isaac; Chen, Yu-Jen; Hsu, Yung-Chin

    2017-04-01

    Schizophrenia is a debilitating mental disorder of which the biological underpinning is still unclear. Increasing evidence in neuroscience has indicated that schizophrenia arises from abnormal connections within or between networks, hence called dysconnectvity syndrome. Recently, we established an automatic method to analyze integrity of the white matter tracts over the whole brain based on diffusion MRI data, named tract-based automatic analysis (TBAA), and used this method to study white matter connection in patients with schizophrenia. We found that alteration of tract integrity is hereditary and inherent; it is found in siblings and in patients in the early phase of disease. Moreover, patients with good treatment outcome and those with poor outcome show distinctly different patterns of alterations, suggesting that these two groups of patients might be distinguishable based on the difference in tract alteration. In summary, the altered tracts revealed by TBAA might become potential biomarkers or trait markers for schizophrenia.

  16. Development of New Contrast Agents for Imaging Function and Metabolism by Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Alexandra Carvalho

    2017-07-01

    Full Text Available Liposomes are interesting nanosystems with a wide range of medical application. One particular application is their ability to enhance contrast in magnetic resonance images; when properly loaded with magnetic/superparamagnetic nanoparticles, this means to act as contrast agents. The design of liposomes loaded with magnetic particles, magnetoliposomes, presents a large number of possibilities depending on the application from image function to metabolism. More interesting is its double function application as theranostics (diagnostics and therapy. The synthesis, characterization, and possible medical applications of two types of magnetoliposomes are reviewed. Their performance will be compared, in particular, their efficiency as contrast agents for magnetic resonance imaging, measured by their relaxivities r 1 and r 2 relating to their particular composition. One of the magnetoliposomes had 1,2-diacyl-sn-glycero-3-phosphocholine (soy as the main phospholipid component, with and without cholesterol, varying its phospholipid to cholesterol molar ratios. The other formulation is a long-circulating liposome composed of 1,2-diacyl-sn-glycero-3-phosphocholine (egg, cholesterol, and 1,2-distearoyl-sn-glycerol-3-phosphoethanolamine- N -[methoxy(polyethylene glycol-2000]. Both nanosystems were loaded with superparamagnetic iron oxide nanoparticles with different sizes and coatings.

  17. Comparison of brain perfusion SPECT abnormalities with anatomical imaging in mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Majid Asadi

    2007-02-01

    Full Text Available Background: Trauma is the most common cause of morbidity and mortality in industrialized countries and also in Iran. Anatomical imaging (AI CT and MRI is helpful in the diagnosis of acute traumatic complications however it is not efficient in the diagnosis of disabling injury syndrome. In contrast, brain perfusion SPECT (Single Photon Emission Computed Tomography can be more useful for evaluation of microvascular structure. This study was designed to compare these two diagnostic methods. Methods: A total of 50 patients who had been suffering from traumatic brain injury for more than 1 year, and were followed as mild traumatic brain injury group according to “the Brain Injury Interdisciplinary Special Interest Group of the Ameri can Congress of Rehabilitation Medicine” criteria, were examined by brain perfusion SPECT and AI. The common anatomical classification of the lobes of brain was used. Results: The male to female ratio was 3:2. The mean age was 32.32±11.8 years and mean post-traumatic time was 1.48±0.65 years. The most common symptoms were headache (60%, agusia (36% and anosmia (32%. Among 400 examined brain lobes in this study, brain perfusion SPECT revealed remarkable abnormality in 76 lobes (19%, but AI determined abnormalities in 38 lobes (9.5% therefore, SPECT was twice sensitive than AI in mild traumatic brain injury (P<0.001. The correlation between SPECT and AI findings was 84%. SPECT was more sensitive than AI in demonstrating brain abnormalities in frontal lobe it was more obvious in the male group however, there was no significant difference between more and less than 30 years old groups. Conclusion: According to the findings of this study, we recommend using brain perfusion SPECT for all patients with chronic complications of head trauma, particularly those who have signs and symptoms of hypofrontalism, even though with some abnormalities in AI.

  18. Magnetic resonance imaging based noninvasive measurements of brain hemodynamics in neonates

    DEFF Research Database (Denmark)

    De Vis, Jill B; Alderliesten, Thomas; Hendrikse, Jeroen

    2016-01-01

    Perinatal disturbances of brain hemodynamics can have a detrimental effect on the brain's parenchyma with consequently adverse neurodevelopmental outcome. Noninvasive, reliable tools to evaluate the neonate's brain hemodynamics are scarce. Advances in magnetic resonance imaging have provided new...

  19. Control of brain metastases using frameless image-guided radiosurgery.

    Science.gov (United States)

    Chen, Joseph C T; Bugoci, Darlene M; Girvigian, Michael R; Miller, Michael J; Arellano, Alonso; Rahimian, Javad

    2009-12-01

    Radiosurgery is an important and well-accepted method in the management of brain metastases. Using conventional frame-based techniques, high lesional control rates are expected. The introduction of image-guided techniques allows for improved patient comfort and workflow. Some controversy exists as to the accuracy of imageguided techniques and consequently the impact they might have on control of brain metastases (as opposed to the level of control achieved with frame-based methods). The authors describe their initial 15-month experience with image-guided radiosurgery (IGRS) using Novalis with ExacTrac for management of brain metastases. The authors reviewed the cases of brain metastasis treated by means of IGRS in their tertiary regional radiation oncology service over a 15-month period. During the study period 54 patients (median age 57.9 years) harboring 108 metastases were treated with IGRS. The median time from cancer diagnosis to development of brain metastasis was 12 months (range 0-144 months). The median tumor volume was 0.98 cm(3) (range 0.03-19.07 cm(3)). The median prescribed dose was 18 Gy to the 80% isodose line (range 14-20 Gy). Lesions were followed with postradiosurgery MR imaging every 2-3 months following treatment. The median follow-up period was 9 months (range 0-20 months). Median actuarial survival was 8.6 months following IGRS. Eight patients with 18 lesions died within the first 2 months after the procedure, before scheduled follow-up imaging. Thus 90 lesions (in 46 patients) were followed up with imaging studies. Lesions that were unchanged or reduced in size were considered to be under control. The 6-month actuarial lesion control rate was 88%. Smaller lesions (Novalis with ExacTrac is equivalent to frame-based radiosurgery methods.

  20. Brain imaging before primary lung cancer resection: a controversial topic.

    Science.gov (United States)

    Hudson, Zoe; Internullo, Eveline; Edey, Anthony; Laurence, Isabel; Bianchi, Davide; Addeo, Alfredo

    2017-01-01

    International and national recommendations for brain imaging in patients planned to undergo potentially curative resection of non-small-cell lung cancer (NSCLC) are variably implemented throughout the United Kingdom [Hudson BJ, Crawford MB, and Curtin J et al (2015) Brain imaging in lung cancer patients without symptoms of brain metastases: a national survey of current practice in England Clin Radiol https://doi.org/10.1016/j.crad.2015.02.007]. However, the recommendations are not based on high-quality evidence and do not take into account cost implications and local resources. Our aim was to determine local practice based on historic outcomes in this patient cohort. This retrospective study took place in a regional thoracic surgical centre in the United Kingdom. Pathology records for all patients who had undergone lung resection with curative intent during the time period January 2012-December 2014 were analysed in October 2015. Electronic pathology and radiology reports were accessed for each patient and data collected about their histological findings, TNM stage, resection margins, and the presence of brain metastases on either pre-operative or post-operative imaging. From the dates given on imaging, we calculated the number of days post-resection that the brain metastases were detected. 585 patients were identified who had undergone resection of their lung cancer. Of these, 471 had accessible electronic radiology records to assess for the radiological evidence of brain metastases. When their electronic records were evaluated, 25/471 (5.3%) patients had radiological evidence of brain metastasis. Of these, five patients had been diagnosed with a brain metastasis at initial presentation and had undergone primary resection of the brain metastasis followed by resection of the lung primary. One patient had been diagnosed with both a primary lung and a primary bowel adenocarcinoma; on review of the case, it was felt that the brain metastasis was more likely to have

  1. Topology-preserving tissue classification of magnetic resonance brain images.

    Science.gov (United States)

    Bazin, Pierre-Louis; Pham, Dzung L

    2007-04-01

    This paper presents a new framework for multiple object segmentation in medical images that respects the topological properties and relationships of structures as given by a template. The technique, known as topology-preserving, anatomy-driven segmentation (TOADS), combines advantages of statistical tissue classification, topology-preserving fast marching methods, and image registration to enforce object-level relationships with little constraint over the geometry. When applied to the problem of brain segmentation, it directly provides a cortical surface with spherical topology while segmenting the main cerebral structures. Validation on simulated and real images characterises the performance of the algorithm with regard to noise, inhomogeneities, and anatomical variations.

  2. Developmental Toxic Effects of Exposure to Chemical Warfare Nerve Agents in Rats: Effects on Brain and Behavior

    Science.gov (United States)

    2015-03-01

    Yourick D (2009) Analyzing large data sets acquired through telemetry from rats exposed to organophosphorus compounds: an EEG study. J Neurosci Methods...AWARD NUMBER: W81XWH-13-2-0082 TITLE: Developmental Toxic Effects of Exposure to Chemical Warfare Nerve Agents in Rats : Effects on Brain and...2014 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Developmental Toxic Effects of Exposure to Chemical Warfare Nerve Agents in Rats : Effects on Brain

  3. Transport, monitoring, and successful brain MR imaging in unsedated neonates

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, Amit M. [St. Louis Children' s Hospital at the Washington University School of Medicine, Department of Pediatrics and Newborn Medicine, St. Louis, MO (United States); St. Louis Children' s Hospital, Division of Newborn Medicine, St. Louis, MO (United States); Neil, Jeffrey J. [St. Louis Children' s Hospital at the Washington University School of Medicine, Department of Neurology, St. Louis, MO (United States); Mallinckrodt Institute of Radiology, St. Louis, MO (United States); McKinstry, Robert C. [Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Inder, Terrie E. [St. Louis Children' s Hospital at the Washington University School of Medicine, Department of Pediatrics and Newborn Medicine, St. Louis, MO (United States); St. Louis Children' s Hospital at the Washington University School of Medicine, Department of Neurology, St. Louis, MO (United States); Mallinckrodt Institute of Radiology, St. Louis, MO (United States)

    2008-03-15

    Neonatal cerebral MR imaging is a sensitive technique for evaluating brain injury in the term and preterm infant. In term encephalopathic infants, MR imaging reliably detects not only the pattern of brain injury but might also provide clues about the timing of injury. In premature infants, MR imaging has surpassed US in the detection of white matter injury, a common lesion in this population. Concerns remain about the safety and transport of sedated neonates for MR examination to radiology suites, which are usually located at a distance from neonatal intensive care units. We present our own institutional experience and guidelines used to optimize the performance of cerebral MR examinations in neonates without sedation or anesthesia. (orig.)

  4. 3D quantitative analysis of brain SPECT images

    Science.gov (United States)

    Loncaric, Sven; Ceskovic, Ivan; Petrovic, Ratimir; Loncaric, Srecko

    2001-07-01

    The main purpose of this work is to develop a computer-based technique for quantitative analysis of 3-D brain images obtained by single photon emission computed tomography (SPECT). In particular, the volume and location of ischemic lesion and penumbra is important for early diagnosis and treatment of infracted regions of the brain. SPECT imaging is typically used as diagnostic tool to assess the size and location of the ischemic lesion. The segmentation method presented in this paper utilizes a 3-D deformable model in order to determine size and location of the regions of interest. The evolution of the model is computed using a level-set implementation of the algorithm. In addition to 3-D deformable model the method utilizes edge detection and region growing for realization of a pre-processing. Initial experimental results have shown that the method is useful for SPECT image analysis.

  5. MR Brain Image Segmentation: A Framework to Compare Different Clustering Techniques

    OpenAIRE

    Laura Caponetti; Giovanna Castellano; Vito Corsini

    2017-01-01

    In Magnetic Resonance (MR) brain image analysis, segmentation is commonly used for detecting, measuring and analyzing the main anatomical structures of the brain and eventually identifying pathological regions. Brain image segmentation is of fundamental importance since it helps clinicians and researchers to concentrate on specific regions of the brain in order to analyze them. However, segmentation of brain images is a difficult task due to high similarities and correlations of intensity amo...

  6. Amide Proton Transfer (APT) MR imaging and Magnetization Transfer (MT) MR imaging of pediatric brain development

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong; Kang, Huiying; Peng, Yun [Beijing Children' s Hospital, Capital Medical University, Imaging Center, Department of Radiology, Beijing (China); Zhao, Xuna [Philips Healthcare, Beijing (China); Jiang, Shanshan; Zhang, Yi; Zhou, Jinyuan [Johns Hopkins University, Division of MR Research, Department of Radiology, Baltimore, MD (United States)

    2016-10-15

    To quantify the brain maturation process during childhood using combined amide proton transfer (APT) and conventional magnetization transfer (MT) imaging at 3 Tesla. Eighty-two neurodevelopmentally normal children (44 males and 38 females; age range, 2-190 months) were imaged using an APT/MT imaging protocol with multiple saturation frequency offsets. The APT-weighted (APTW) and MT ratio (MTR) signals were quantitatively analyzed in multiple brain areas. Age-related changes in MTR and APTW were evaluated with a non-linear regression analysis. The APTW signals followed a decreasing exponential curve with age in all brain regions measured (R{sup 2} = 0.7-0.8 for the corpus callosum, frontal and occipital white matter, and centrum semiovale). The most significant changes appeared within the first year. At maturation, larger decreases in APTW and lower APTW values were found in the white matter. On the contrary, the MTR signals followed an increasing exponential curve with age in the same brain regions measured, with the most significant changes appearing within the initial 2 years. There was an inverse correlation between the MTR and APTW signal intensities during brain maturation. Together with MT imaging, protein-based APT imaging can provide additional information in assessing brain myelination in the paediatric population. (orig.)

  7. Molecular imaging of the brain. Using multi-quantum coherence and diagnostics of brain disorders

    Energy Technology Data Exchange (ETDEWEB)

    Kaila, M.M. [New South Wales Univ., Sydney, NSW (Australia). School of Physics; Kaila, Rakhi [Univ. of New South Wales, Sydney (Australia). School of Medicine

    2013-11-01

    Explains the basics of the MRI and its use in the diagnostics and the treatment of the human brain disorders. Examines multi-quantum magnetic resonance imaging methods and the diagnostics of brain disorders. Covers how in a non-invasive manner one can diagnose diseases of the brain. This book examines multi-quantum magnetic resonance imaging methods and the diagnostics of brain disorders. It consists of two Parts. The part I is initially devoted towards the basic concepts of the conventional single quantum MRI techniques. It is supplemented by the basic knowledge required to understand multi-quantum MRI. Practical illustrations are included both on recent developments in conventional MRI and the MQ-MRI. This is to illustrate the connection between theoretical concepts and their scope in the clinical applications. The Part II initially sets out the basic details about quadrupole charge distribution present in certain nuclei and their importance about the functions they perform in our brain. Some simplified final mathematical expressions are included to illustrate facts about the basic concepts of the quantum level interactions between magnetic dipole and the electric quadrupole behavior of useful nuclei present in the brain. Selected practical illustrations, from research and clinical practices are included to illustrate the newly emerging ideas and techniques. The reader should note that the two parts of the book are written with no interdependence. One can read them quite independently.

  8. Role of infectious agents in the carcinogenesis of brain and head and neck cancers

    Directory of Open Access Journals (Sweden)

    Alibek Kenneth

    2013-02-01

    Full Text Available Abstract This review concentrates on tumours that are anatomically localised in head and neck regions. Brain cancers and head and neck cancers together account for more than 873,000 cases annually worldwide, with an increasing incidence each year. With poor survival rates at late stages, brain and head and neck cancers represent serious conditions. Carcinogenesis is a multi-step process and the role of infectious agents in this progression has not been fully identified. A major problem with such research is that the role of many infectious agents may be underestimated due to the lack of or inconsistency in experimental data obtained globally. In the case of brain cancer, no infection has been accepted as directly oncogenic, although a number of viruses and parasites are associated with the malignancy. Our analysis of the literature showed the presence of human cytomegalovirus (HCMV in distinct types of brain tumour, namely glioblastoma multiforme (GBM and medulloblastoma. In particular, there are reports of viral protein in up to 100% of GBM specimens. Several epidemiological studies reported associations of brain cancer and toxoplasmosis seropositivity. In head and neck cancers, there is a distinct correlation between Epstein-Barr virus (EBV and nasopharyngeal carcinoma (NPC. Considering that almost every undifferentiated NPC is EBV-positive, virus titer levels can be measured to screen high-risk populations. In addition there is an apparent association between human papilloma virus (HPV and head and neck squamous cell carcinoma (HNSCC; specifically, 26% of HNSCCs are positive for HPV. HPV type 16 was the most common type detected in HNSCCs (90% and its dominance is even greater than that reported in cervical carcinoma. Although there are many studies showing an association of infectious agents with cancer, with various levels of involvement and either a direct or indirect causative effect, there is a scarcity of articles covering the role of

  9. Optimization of image reconstruction conditions with phantoms for brain FDG and amyloid PET imaging

    National Research Council Canada - National Science Library

    Akamatsu, Go; Ikari, Yasuhiko; Nishio, Tomoyuki; Nishida, Hiroyuki; Ohnishi, Akihito; Aita, Kazuki; Sasaki, Masahiro; Sasaki, Masayuki; Senda, Michio

    2016-01-01

    The purpose of this study was to optimize image reconstruction conditions for brain 18F-FDG, 11C-PiB, 18F-florbetapir and 18F-flutemetamol PET imaging with Discovery-690 PET/CT for diagnosis and research on Alzheimer’s disease (AD...

  10. Coordinate-based versus structural approaches to brain image analysis.

    Science.gov (United States)

    Mangin, J-F; Rivière, D; Coulon, O; Poupon, C; Cachia, A; Cointepas, Y; Poline, J-B; Le Bihan, D; Régis, J; Papadopoulos-Orfanos, D

    2004-02-01

    A basic issue in neurosciences is to look for possible relationships between brain architecture and cognitive models. The lack of architectural information in magnetic resonance images, however, has led the neuroimaging community to develop brain mapping strategies based on various coordinate systems without accurate architectural content. Therefore, the relationships between architectural and functional brain organizations are difficult to study when analyzing neuroimaging experiments. This paper advocates that the design of new brain image analysis methods inspired by the structural strategies often used in computer vision may provide better ways to address these relationships. The key point underlying this new framework is the conversion of the raw images into structural representations before analysis. These representations are made up of data-driven elementary features like activated clusters, cortical folds or fiber bundles. Two classes of methods are introduced. Inference of structural models via matching across a set of individuals is described first. This inference problem is illustrated by the group analysis of functional statistical parametric maps (SPMs). Then, the matching of new individual data with a priori known structural models is described, using the recognition of the cortical sulci as a prototypical example.

  11. Fetal magnetic resonance imaging (MRI) of ischemic brain injury.

    Science.gov (United States)

    de Laveaucoupet, J; Audibert, F; Guis, F; Rambaud, C; Suarez, B; Boithias-Guérot, C; Musset, D

    2001-09-01

    The aim of the present study was to demonstrate the usefulness of fetal magnetic resonance imaging (MRI) in ischemic brain injury. We report seven cases of fetal brain ischemia prenatally suspected on ultrasound (US) and confirmed by fetal MRI. Sonographic abnormalities included ventricular dilatation (n=3), microcephaly (n=1), twin pregnancy with in utero death of a twin and suspected cerebral lesion in the surviving co-twin (n=3). MRI was performed with a 1.0 T unit using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences between 28 and 35 weeks of gestation. US and MRI images were compared with pathologic findings or postnatal imaging. MRI diagnosed hydranencephaly (n=1), porencephaly (n=2), multicystic encephalomalacia (n=2), unilateral capsular ischemia (n=1), corpus callosum and cerebral atrophy (n=1). In comparison with US, visualization of fetal brain anomalies was superior with MRI. The present cases demonstrate that MRI is a valuable complementary means of investigation when a brain pathology is discovered or suspected during prenatal US. Copyright 2001 John Wiley & Sons, Ltd.

  12. Intraoperative fluorescence imaging for personalized brain tumor resection: Current state and future directions

    Directory of Open Access Journals (Sweden)

    Evgenii Belykh

    2016-10-01

    Full Text Available Introduction: Fluorescence-guided surgery is one of the rapidly emerging methods of surgical theranostics. In this review, we summarize current fluorescence techniques used in neurosurgical practice for brain tumor patients, as well as future applications of recent laboratory and translational studies.Methods: Review of the literature.Results: A wide spectrum of fluorophores that have been tested for brain surgery is reviewed. Beginning with a fluorescein sodium application in 1948 by Moore, fluorescence guided brain tumor surgery is either routinely applied in some centers or is under active study in clinical trials. Besides the trinity of commonly used drugs (fluorescein sodium, 5-ALA and ICG, less studied fluorescent stains, such as tetracyclines, cancer-selective alkylphosphocholine analogs, cresyl violet, acridine orange, and acriflavine can be used for rapid tumor detection and pathological tissue examination. Other emerging agents such as activity-based probes and targeted molecular probes that can provide biomolecular specificity for surgical visualization and treatment are reviewed. Furthermore, we review available engineering and optical solutions for fluorescent surgical visualization. Instruments for fluorescent-guided surgery are divided into wide-field imaging systems and hand-held probes. Recent advancements in quantitative fluorescence-guided surgery are discussed.Conclusion: We are standing on the doorstep of the era of marker-assisted tumor management. Innovations in the fields of surgical optics, computer image analysis, and molecular bioengineering are advancing fluorescence-guided tumor resection paradigms, leading to cell-level approaches to visualization and resection of brain tumors.

  13. Lupus anticoagulant: correlation with magnetic resonance imaging of brain lesions.

    Science.gov (United States)

    Molad, Y; Sidi, Y; Gornish, M; Lerner, M; Pinkhas, J; Weinberger, A

    1992-04-01

    Brain magnetic resonance imaging (MRI) was performed in 21 patients with systemic lupus erythematosus (SLE) with and without lupus anticoagulant (LAC), one lupus-like patient and 5 patients with primary antiphospholipid antibody syndrome. Thirteen patients had white matter focal brain lesions on MRI, 10 of whom had LAC (p = 0.03). We found no correlation between these lesions and neurologic manifestations, nor any clinical or serologic indices of activity of SLE. Our MRI lesions were similar to those described in multiple sclerosis and may indicate a similar pathologic process.

  14. Hybrid material as contrast agent in magnetic resonance images

    OpenAIRE

    Botella Asunción, Pablo; Cabrera García, Alejandro

    2015-01-01

    [EN] The invention relates to a contrast agent of magnetic resonance based on a hybrid material formed by an organo-metallic core derived from Prussian blue and a silica cover, and optionally, molecules of a poly(ethylene glycol), a fluorescent agent, a radio nucleus and/or a substance that directs to specific receptors, cells or tissues, joined by covalent bonding to the surface of the inorganic cover.

  15. Ultrasound contrast agent imaging: Real-time imaging of the superharmonics

    Energy Technology Data Exchange (ETDEWEB)

    Peruzzini, D.; Viti, J. [MSD lab, Department of Information Engineering, Univ of Florence, Via S.Marta, 3, 50139 Firenze (Italy); Erasmus MC, ’s-Gravendijkwal 230, Faculty Building, Ee 2302, 3015 CE Rotterdam (Netherlands); Tortoli, P. [MSD lab, Department of Information Engineering, Univ of Florence, Via S.Marta, 3, 50139 Firenze (Italy); Verweij, M. D. [Acoustical Wavefield Imaging, ImPhys, Delft Univ Technology, van der Waalsweg 8, 2628 CH Delft (Netherlands); Jong, N. de; Vos, H. J., E-mail: h.vos@erasmusmc.nl [Erasmus MC, ’s-Gravendijkwal 230, Faculty Building, Ee 2302, 3015 CE Rotterdam (Netherlands); Acoustical Wavefield Imaging, ImPhys, Delft Univ Technology, van der Waalsweg 8, 2628 CH Delft (Netherlands)

    2015-10-28

    Currently, in medical ultrasound contrast agent (UCA) imaging the second harmonic scattering of the microbubbles is regularly used. This scattering is in competition with the signal that is caused by nonlinear wave propagation in tissue. It was reported that UCA imaging based on the third or higher harmonics, i.e. “superharmonic” imaging, shows better contrast. However, the superharmonic scattering has a lower signal level compared to e.g. second harmonic signals. This study investigates the contrast-to-tissue ratio (CTR) and signal to noise ratio (SNR) of superharmonic UCA scattering in a tissue/vessel mimicking phantom using a real-time clinical scanner. Numerical simulations were performed to estimate the level of harmonics generated by the microbubbles. Data were acquired with a custom built dual-frequency cardiac phased array probe. Fundamental real-time images were produced while beam formed radiofrequency (RF) data was stored for further offline processing. The phantom consisted of a cavity filled with UCA surrounded by tissue mimicking material. The acoustic pressure in the cavity of the phantom was 110 kPa (MI = 0.11) ensuring non-destructivity of UCA. After processing of the acquired data from the phantom, the UCA-filled cavity could be clearly observed in the images, while tissue signals were suppressed at or below the noise floor. The measured CTR values were 36 dB, >38 dB, and >32 dB, for the second, third, and fourth harmonic respectively, which were in agreement with those reported earlier for preliminary contrast superharmonic imaging. The single frame SNR values (in which ‘signal’ denotes the signal level from the UCA area) were 23 dB, 18 dB, and 11 dB, respectively. This indicates that noise, and not the tissue signal, is the limiting factor for the UCA detection when using the superharmonics in nondestructive mode.

  16. Radionuclide brain imaging in acquired immunodeficiency syndrome (AIDS)

    Energy Technology Data Exchange (ETDEWEB)

    Costa, D.C.; Gacinovic, S.; Miller, R.F. [London University College Medical School, Middlesex Hospital, London (United Kingdom)

    1995-09-01

    Infection with the Human Immunodeficiency Virus type 1 (HIV-1) may produce a variety of central nervous system (CNS) symptoms and signs. CNS involvement in patients with the Acquired Immunodeficiency Syndrome (AIDS) includes AIDS dementia complex or HIV-1 associated cognitive/motor complex (widely known as HIV encephalopathy), progressive multifocal leucoencephalopathy (PML), opportunistic infections such as Toxoplasma gondii, TB, Cryptococcus and infiltration by non-Hodgkin`s B cell lymphoma. High resolution structural imaging investigations, either X-ray Computed Tomography (CT scan) or Magnetic Resonance Imaging (MRI) have contributed to the understanding and definition of cerebral damage caused by HIV encephalopathy. Atrophy and mainly high signal scattered white matter abnormalities are commonly seen with MRI. PML produces focal white matter high signal abnormalities due to multiple foci of demyelination. However, using structural imaging techniques there are no reliable parameters to distinguish focal lesions due to opportunistic infection (Toxoplasma gondii abscess) from neoplasm (lymphoma infiltration). It is studied the use of radionuclide brain imaging techniques in the investigation of HIV infected patients. Brain perfusion Single Photon Emission Tomography (SPET), neuroreceptor and Positron Emission Tomography (PET) studies are reviewed. Greater emphasis is put on the potential of some radiopharmaceuticals, considered to be brain tumour markers, to distinguish intracerebral lymphoma infiltration from Toxoplasma infection. SPET with {sup 201}Tl using quantification (tumour to non-tumour radioactivity ratios) appears a very promising technique to identify intracerebral lymphoma.

  17. Bacterial brain abscesses: prognostic value of an imaging severity index

    Energy Technology Data Exchange (ETDEWEB)

    Demir, M.K. [Department of Radiology, Trakya University School of Medicine, Edirne (Turkey)]. E-mail: demirkemal@superonline.com; Hakan, T. [Department of Neurosurgery, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Kilicoglu, G. [Department of Radiology, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Ceran, N. [Department of Infectious Disease, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Berkman, M.Z. [Department of Neurosurgery, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Erdem, I. [Department of Infectious Disease, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Goektas, P. [Department of Infectious Disease, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey)

    2007-06-15

    Aim: To assess the correlation between imaging findings [computed tomography (CT) or magnetic resonance imaging (MRI)] and neurological status before and after the treatment of bacterial brain abscesses. Materials and methods: CT and MRI images of 96 patients with brain abscesses were retrospectively evaluated in terms of the number, location and size of lesions, and the presence and extent of perilesional oedema and midline shift. An imaging severity index (ISI) based on these different radiological parameters was calculated. Initial Glasgow Coma Scale (GCS) scores and ISI were assessed and the prognostic value of these two indices was calculated. The Pearson correlation test, Mann-Whitney test, Chi-square test, receiver-operating characteristic (ROC) analysis, together with comparison of ROC analyses and Fisher's exact test were used. Results: There was a negative correlation between ISI and the initial GCS values: ISI increased as the GCS score decreased, indicating an inverse relationship (r = -0.51, p < 0.0001). There was a significant difference between the ISI and GCS scores of patients with an adverse event compared with patients with good recovery. Outcome was significantly worse in patients with initial ISI over the calculated cut-off values of 8 points or GCS scores under the cut-off value of 13 points. Conclusion: ISI is a useful prognostic indicator for bacterial brain abscess patients and correlates strongly with the patient outcome for all parameters studied. ISI score had a better prognostic value than GCS.

  18. Brain surface maps from 3-D medical images

    Science.gov (United States)

    Lu, Jiuhuai; Hansen, Eric W.; Gazzaniga, Michael S.

    1991-06-01

    The anatomic and functional localization of brain lesions for neurologic diagnosis and brain surgery is facilitated by labeling the cortical surface in 3D images. This paper presents a method which extracts cortical contours from magnetic resonance (MR) image series and then produces a planar surface map which preserves important anatomic features. The resultant map may be used for manual anatomic localization as well as for further automatic labeling. Outer contours are determined on MR cross-sectional images by following the clear boundaries between gray matter and cerebral-spinal fluid, skipping over sulci. Carrying this contour below the surface by shrinking it along its normal produces an inner contour that alternately intercepts gray matter (sulci) and white matter along its length. This procedure is applied to every section in the set, and the image (grayscale) values along the inner contours are radially projected and interpolated onto a semi-cylindrical surface with axis normal to the slices and large enough to cover the whole brain. A planar map of the cortical surface results by flattening this cylindrical surface. The projection from inner contour to cylindrical surface is unique in the sense that different points on the inner contour correspond to different points on the cylindrical surface. As the outer contours are readily obtained by automatic segmentation, cortical maps can be made directly from an MR series.

  19. Imaging brain microstructure with diffusion MRI: practicality and applications.

    Science.gov (United States)

    Alexander, Daniel C; Dyrby, Tim B; Nilsson, Markus; Zhang, Hui

    2017-11-29

    This article gives an overview of microstructure imaging of the brain with diffusion MRI and reviews the state of the art. The microstructure-imaging paradigm aims to estimate and map microscopic properties of tissue using a model that links these properties to the voxel scale MR signal. Imaging techniques of this type are just starting to make the transition from the technical research domain to wide application in biomedical studies. We focus here on the practicalities of both implementing such techniques and using them in applications. Specifically, the article summarizes the relevant aspects of brain microanatomy and the range of diffusion-weighted MR measurements that provide sensitivity to them. It then reviews the evolution of mathematical and computational models that relate the diffusion MR signal to brain tissue microstructure, as well as the expanding areas of application. Next we focus on practicalities of designing a working microstructure imaging technique: model selection, experiment design, parameter estimation, validation, and the pipeline of development of this class of technique. The article concludes with some future perspectives on opportunities in this topic and expectations on how the field will evolve in the short-to-medium term. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Automatic segmentation of MR brain images in multiple sclerosis patients

    Science.gov (United States)

    Avula, Ramesh T. V.; Erickson, Bradley J.

    1996-04-01

    A totally automatic scheme for segmenting brain from extracranial tissues and to classify all intracranial voxels as CSF, gray matter (GM), white matter (WM), or abnormality such as multiple sclerosis (MS) lesions is presented in this paper. It is observed that in MR head images, if a tissue's intensity values are normalized, its relationship to the other tissues is essentially constant for a given type of image. Based on this approach, the subcutaneous fat surrounding the head is normalized to classify other tissues. Spatially registered 3 mm MR head image slices of T1 weighted, fast spin echo [dual echo T2 weighted and proton density (PD) weighted images] and fast fluid attenuated inversion recovery (FLAIR) sequences are used for segmentation. Subcutaneous fat surrounding the skull was identified based on intensity thresholding from T1 weighted images. A multiparametric space map was developed for CSF, GM and WM by normalizing each tissue with respect to the mean value of corresponding subcutaneous fat on each pulse sequence. To reduce the low frequency noise without blurring the fine morphological high frequency details an anisotropic diffusion filter was applied to all images before segmentation. An initial slice by slice classification was followed by morphological operations to delete any brides connecting extracranial segments. Finally 3-dimensional region growing of the segmented brain extracts GM, WM and pathology. The algorithm was tested on sequential scans of 10 patients with MS lesions. For well registered sequences, tissues and pathology have been accurately classified. This procedure does not require user input or image training data sets, and shows promise for automatic classification of brain and pathology.

  1. Development of integrated semiconductor optical sensors for functional brain imaging

    Science.gov (United States)

    Lee, Thomas T.

    Optical imaging of neural activity is a widely accepted technique for imaging brain function in the field of neuroscience research, and has been used to study the cerebral cortex in vivo for over two decades. Maps of brain activity are obtained by monitoring intensity changes in back-scattered light, called Intrinsic Optical Signals (IOS), that correspond to fluctuations in blood oxygenation and volume associated with neural activity. Current imaging systems typically employ bench-top equipment including lamps and CCD cameras to study animals using visible light. Such systems require the use of anesthetized or immobilized subjects with craniotomies, which imposes limitations on the behavioral range and duration of studies. The ultimate goal of this work is to overcome these limitations by developing a single-chip semiconductor sensor using arrays of sources and detectors operating at near-infrared (NIR) wavelengths. A single-chip implementation, combined with wireless telemetry, will eliminate the need for immobilization or anesthesia of subjects and allow in vivo studies of free behavior. NIR light offers additional advantages because it experiences less absorption in animal tissue than visible light, which allows for imaging through superficial tissues. This, in turn, reduces or eliminates the need for traumatic surgery and enables long-term brain-mapping studies in freely-behaving animals. This dissertation concentrates on key engineering challenges of implementing the sensor. This work shows the feasibility of using a GaAs-based array of vertical-cavity surface emitting lasers (VCSELs) and PIN photodiodes for IOS imaging. I begin with in-vivo studies of IOS imaging through the skull in mice, and use these results along with computer simulations to establish minimum performance requirements for light sources and detectors. I also evaluate the performance of a current commercial VCSEL for IOS imaging, and conclude with a proposed prototype sensor.

  2. Brain surface motion imaging to predict adhesions between meningiomas and the brain surface

    Energy Technology Data Exchange (ETDEWEB)

    Taoka, Toshiaki; Yamatani, Yuya; Akashi, Toshiaki; Miyasaka, Toshiteru; Emura, Tomoko; Kichikawa, Kimihiko [Nara Medical University, Department of Radiology, Nara (Japan); Yamada, Syuichi; Nakase, Hiroyuki [Nara Medical University, Department of Neurosurgery, Nara (Japan)

    2010-11-15

    ''Brain surface motion imaging'' (BSMI) is the subtraction of pulse-gated, 3D, heavily T2-weighted image of two different phases of cerebrospinal fluid (CSF) pulsation, which enables the assessment of the dynamics of brain surface pulsatile motion. The purpose of this study was to evaluate the feasibility of this imaging method for providing presurgical information about adhesions between meningiomas and the brain surface. Eighteen cases with surgically resected meningioma in whom BSMI was presurgically obtained were studied. BSMI consisted of two sets of pulse-gated, 3D, heavily T2-weighted, fast spin echo scans. Images of the systolic phase and the diastolic phase were obtained, and subtraction was performed with 3D motion correction. We analyzed the presence of band-like texture surrounding the tumor and judged the degree of motion discrepancy as ''total,'' ''partial,'' or ''none.'' The correlation between BSMI and surgical findings was evaluated. For cases with partial adhesions, agreements in the locations of the adhesions were also evaluated. On presurgical BSMI, no motion discrepancy was seen in eight cases, partial in six cases, and total in four cases. These presurgical predictions about adhesions and surgical findings agreed in 13 cases (72.2%). The locations of adhesions agreed in five of six cases with partial adhesions. In the current study, BSMI could predict brain and meningioma adhesions correctly in 72.2% of cases, and adhesion location could also be predicted. This imaging method appears to provide presurgical information about brain/meningioma adhesions. (orig.)

  3. Biocytin-derived MRI contrast agent for longitudinal brain connectivity studies.

    Science.gov (United States)

    Mishra, Anurag; Schüz, Almut; Engelmann, Jörn; Beyerlein, Michael; Logothetis, Nikos K; Canals, Santiago

    2011-10-19

    To investigate the connectivity of brain networks noninvasively and dynamically, we have developed a new strategy to functionalize neuronal tracers and designed a biocompatible probe that can be visualized in vivo using magnetic resonance imaging (MRI). Furthermore, the multimodal design used allows combined ex vivo studies with microscopic spatial resolution by conventional histochemical techniques. We present data on the functionalization of biocytin, a well-known neuronal tract tracer, and demonstrate the validity of the approach by showing brain networks of cortical connectivity in live rats under MRI, together with the corresponding microscopic details, such as fibers and neuronal morphology under light microscopy. We further demonstrate that the developed molecule is the first MRI-visible probe to preferentially trace retrograde connections. Our study offers a new platform for the development of multimodal molecular imaging tools of broad interest in neuroscience, that capture in vivo the dynamics of large scale neural networks together with their microscopic characteristics, thereby spanning several organizational levels.

  4. MR to CT registration of brains using image synthesis

    Science.gov (United States)

    Roy, Snehashis; Carass, Aaron; Jog, Amod; Prince, Jerry L.; Lee, Junghoon

    2014-03-01

    Computed tomography (CT) is the preferred imaging modality for patient dose calculation for radiation therapy. Magnetic resonance (MR) imaging (MRI) is used along with CT to identify brain structures due to its superior soft tissue contrast. Registration of MR and CT is necessary for accurate delineation of the tumor and other structures, and is critical in radiotherapy planning. Mutual information (MI) or its variants are typically used as a similarity metric to register MRI to CT. However, unlike CT, MRI intensity does not have an accepted calibrated intensity scale. Therefore, MI-based MR-CT registration may vary from scan to scan as MI depends on the joint histogram of the images. In this paper, we propose a fully automatic framework for MR-CT registration by synthesizing a synthetic CT image from MRI using a co-registered pair of MR and CT images as an atlas. Patches of the subject MRI are matched to the atlas and the synthetic CT patches are estimated in a probabilistic framework. The synthetic CT is registered to the original CT using a deformable registration and the computed deformation is applied to the MRI. In contrast to most existing methods, we do not need any manual intervention such as picking landmarks or regions of interests. The proposed method was validated on ten brain cancer patient cases, showing 25% improvement in MI and correlation between MR and CT images after registration compared to state-of-the-art registration methods.

  5. MR to CT Registration of Brains using Image Synthesis.

    Science.gov (United States)

    Roy, Snehashis; Carass, Aaron; Jog, Amod; Prince, Jerry L; Lee, Junghoon

    2014-03-21

    Computed tomography (CT) is the standard imaging modality for patient dose calculation for radiation therapy. Magnetic resonance (MR) imaging (MRI) is used along with CT to identify brain structures due to its superior soft tissue contrast. Registration of MR and CT is necessary for accurate delineation of the tumor and other structures, and is critical in radiotherapy planning. Mutual information (MI) or its variants are typically used as a similarity metric to register MRI to CT. However, unlike CT, MRI intensity does not have an accepted calibrated intensity scale. Therefore, MI-based MR-CT registration may vary from scan to scan as MI depends on the joint histogram of the images. In this paper, we propose a fully automatic framework for MR-CT registration by synthesizing a synthetic CT image from MRI using a co-registered pair of MR and CT images as an atlas. Patches of the subject MRI are matched to the atlas and the synthetic CT patches are estimated in a probabilistic framework. The synthetic CT is registered to the original CT using a deformable registration and the computed deformation is applied to the MRI. In contrast to most existing methods, we do not need any manual intervention such as picking landmarks or regions of interests. The proposed method was validated on ten brain cancer patient cases, showing 25% improvement in MI and correlation between MR and CT images after registration compared to state-of-the-art registration methods.

  6. Automatic segmentation of brain images: selection of region extraction methods

    Science.gov (United States)

    Gong, Leiguang; Kulikowski, Casimir A.; Mezrich, Reuben S.

    1991-07-01

    In automatically analyzing brain structures from a MR image, the choice of low level region extraction methods depends on the characteristics of both the target object and the surrounding anatomical structures in the image. The authors have experimented with local thresholding, global thresholding, and other techniques, using various types of MR images for extracting the major brian landmarks and different types of lesions. This paper describes specifically a local- binary thresholding method and a new global-multiple thresholding technique developed for MR image segmentation and analysis. The initial testing results on their segmentation performance are presented, followed by a comparative analysis of the two methods and their ability to extract different types of normal and abnormal brain structures -- the brain matter itself, tumors, regions of edema surrounding lesions, multiple sclerosis lesions, and the ventricles of the brain. The analysis and experimental results show that the global multiple thresholding techniques are more than adequate for extracting regions that correspond to the major brian structures, while local binary thresholding is helpful for more accurate delineation of small lesions such as those produced by MS, and for the precise refinement of lesion boundaries. The detection of other landmarks, such as the interhemispheric fissure, may require other techniques, such as line-fitting. These experiments have led to the formulation of a set of generic computer-based rules for selecting the appropriate segmentation packages for particular types of problems, based on which further development of an innovative knowledge- based, goal directed biomedical image analysis framework is being made. The system will carry out the selection automatically for a given specific analysis task.

  7. Vessel segmentation in 4D arterial spin labeling magnetic resonance angiography images of the brain

    Science.gov (United States)

    Phellan, Renzo; Lindner, Thomas; Falcão, Alexandre X.; Forkert, Nils D.

    2017-03-01

    4D arterial spin labeling magnetic resonance angiography (4D ASL MRA) is a non-invasive and safe modality for cerebrovascular imaging procedures. It uses the patient's magnetically labeled blood as intrinsic contrast agent, so that no external contrast media is required. It provides important 3D structure and blood flow information but a sufficient cerebrovascular segmentation is important since it can help clinicians to analyze and diagnose vascular diseases faster, and with higher confidence as compared to simple visual rating of raw ASL MRA images. This work presents a new method for automatic cerebrovascular segmentation in 4D ASL MRA images of the brain. In this process images are denoised, corresponding image label/control image pairs of the 4D ASL MRA sequences are subtracted, and temporal intensity averaging is used to generate a static representation of the vascular system. After that, sets of vessel and background seeds are extracted and provided as input for the image foresting transform algorithm to segment the vascular system. Four 4D ASL MRA datasets of the brain arteries of healthy subjects and corresponding time-of-flight (TOF) MRA images were available for this preliminary study. For evaluation of the segmentation results of the proposed method, the cerebrovascular system was automatically segmented in the high-resolution TOF MRA images using a validated algorithm and the segmentation results were registered to the 4D ASL datasets. Corresponding segmentation pairs were compared using the Dice similarity coefficient (DSC). On average, a DSC of 0.9025 was achieved, indicating that vessels can be extracted successfully from 4D ASL MRA datasets by the proposed segmentation method.

  8. The history of urea as a hyperosmolar agent to decrease brain swelling.

    Science.gov (United States)

    Otvos, Balint; Kshettry, Varun R; Benzel, Edward C

    2014-04-01

    In 1919, it was observed that intravascular osmolar shifts could collapse the thecal sac and diminish the ability to withdraw CSF from the lumbar cistern. This led to the notion that hyperosmolar compounds could ameliorate brain swelling. Since then, various therapeutic interventions have been used for the reduction of intracranial pressure and brain volume. Urea was first used as an osmotic agent for the reduction of brain volume in 1950. It was associated with greater efficacy and consistency than alternatives such as hyperosmolar glucose. Its use became the standard of clinical practice by 1957, in both the intensive care unit and operating room, to reduce intracranial pressure and brain bulk and was the first hyperosmolar compound to have widespread use. However, the prime of urea was rather short lived. Reports of side effects and complications associated with urea emerged. These included coagulopathy, hemoglobinuria, electrocardiography changes, tissue necrosis with extravasation, and a significant potential for rebound intracranial hypertension. Mannitol was introduced in 1961 as a comparable and potentially superior alternative to urea. However, mannitol was initially purported to be less effective at rapidly reducing intracranial pressure. The debate over the two compounds continued for a decade until mannitol eventually replaced urea by the late 1960s and early 1970s as the hyperosmolar agent of choice due to the ease of preparation, chemical stability, and decreased side effect profile. Although urea is not currently the standard of care today, its rise and eventual replacement by mannitol played a seminal role in both our understanding of cerebral edema and the establishment of strategies for its management.

  9. Functional brain imaging: an evidence-based analysis.

    Science.gov (United States)

    2006-01-01

    The objective of this analysis is to review a spectrum of functional brain imaging technologies to identify whether there are any imaging modalities that are more effective than others for various brain pathology conditions. This evidence-based analysis reviews magnetoencephalography (MEG), magnetic resonance spectroscopy (MRS), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI) for the diagnosis or surgical management of the following conditions: Alzheimer's disease (AD), brain tumours, epilepsy, multiple sclerosis (MS), and Parkinson's disease (PD). TARGET POPULATION AND CONDITION Alzheimer's disease is a progressive, degenerative, neurologic condition characterized by cognitive impairment and memory loss. The Canadian Study on Health and Aging estimated that there will be 97,000 incident cases (about 60,000 women) of dementia (including AD) in Canada in 2006. In Ontario, there will be an estimated 950 new cases and 580 deaths due to brain cancer in 2006. Treatments for brain tumours include surgery and radiation therapy. However, one of the limitations of radiation therapy is that it damages tissue though necrosis and scarring. Computed tomography (CT) and magnetic resonance imaging (MRI) may not distinguish between radiation effects and resistant tissue, creating a potential role for functional brain imaging. Epilepsy is a chronic disorder that provokes repetitive seizures. In Ontario, the rate of epilepsy is estimated to be 5 cases per 1,000 people. Most people with epilepsy are effectively managed with drug therapy; but about 50% do not respond to drug therapy. Surgical resection of the seizure foci may be considered in these patients, and functional brain imaging may play a role in localizing the seizure foci. Multiple sclerosis is a progressive, inflammatory, demyelinating disease of the central nervous system (CNS). The cause of MS is unknown; however, it is thought to be due to a combination of etiologies, including

  10. A Cellular Perspective on Brain Energy Metabolism and Functional Imaging

    KAUST Repository

    Magistretti, Pierre J.

    2015-05-01

    The energy demands of the brain are high: they account for at least 20% of the body\\'s energy consumption. Evolutionary studies indicate that the emergence of higher cognitive functions in humans is associated with an increased glucose utilization and expression of energy metabolism genes. Functional brain imaging techniques such as fMRI and PET, which are widely used in human neuroscience studies, detect signals that monitor energy delivery and use in register with neuronal activity. Recent technological advances in metabolic studies with cellular resolution have afforded decisive insights into the understanding of the cellular and molecular bases of the coupling between neuronal activity and energy metabolism and pointat a key role of neuron-astrocyte metabolic interactions. This article reviews some of the most salient features emerging from recent studies and aims at providing an integration of brain energy metabolism across resolution scales. © 2015 Elsevier Inc.

  11. Data-driven forward model inference for EEG brain imaging

    DEFF Research Database (Denmark)

    Hansen, Sofie Therese; Hauberg, Søren; Hansen, Lars Kai

    2016-01-01

    Electroencephalography (EEG) is a flexible and accessible tool with excellent temporal resolution but with a spatial resolution hampered by volume conduction. Reconstruction of the cortical sources of measured EEG activity partly alleviates this problem and effectively turns EEG into a brain......-of-concept study, we show that, even when anatomical knowledge is unavailable, a suitable forward model can be estimated directly from the EEG. We propose a data-driven approach that provides a low-dimensional parametrization of head geometry and compartment conductivities, built using a corpus of forward models....... Combined with only a recorded EEG signal, we are able to estimate both the brain sources and a person-specific forward model by optimizing this parametrization. We thus not only solve an inverse problem, but also optimize over its specification. Our work demonstrates that personalized EEG brain imaging...

  12. CARS and non-linear microscopy imaging of brain tumors

    Science.gov (United States)

    Galli, Roberta; Uckermann, Ortrud; Tamosaityte, Sandra; Geiger, Kathrin; Schackert, Gabriele; Steiner, Gerald; Koch, Edmund; Kirsch, Matthias

    2013-06-01

    Nonlinear optical microscopy offers a series of techniques that have the potential to be applied in vivo, for intraoperative identification of tumor border and in situ pathology. By addressing the different content of lipids that characterize the tumors with respect to the normal brain tissue, CARS microscopy enables to discern primary and secondary brain tumors from healthy tissue. A study performed in mouse models shows that the reduction of the CARS signal is a reliable quantity to identify brain tumors, irrespective from the tumor type. Moreover it enables to identify tumor borders and infiltrations at a cellular resolution. Integration of CARS with autogenous TPEF and SHG adds morphological and compositional details about the tissue. Examples of multimodal CARS imaging of different human tumor biopsies demonstrate the ability of the technique to retrieve information useful for histopathological diagnosis.

  13. Melanin-Based Contrast Agents for Biomedical Optoacoustic Imaging and Theranostic Applications.

    Science.gov (United States)

    Longo, Dario Livio; Stefania, Rachele; Aime, Silvio; Oraevsky, Alexander

    2017-08-07

    Optoacoustic imaging emerged in early 1990s as a new biomedical imaging technology that generates images by illuminating tissues with short laser pulses and detecting resulting ultrasound waves. This technique takes advantage of the spectroscopic approach to molecular imaging, and delivers high-resolution images in the depth of tissue. Resolution of the optoacoustic imaging is scalable, so that biomedical systems from cellular organelles to large organs can be visualized and, more importantly, characterized based on their optical absorption coefficient, which is proportional to the concentration of absorbing chromophores. Optoacoustic imaging was shown to be useful in both preclinical research using small animal models and in clinical applications. Applications in the field of molecular imaging offer abundant opportunities for the development of highly specific and effective contrast agents for quantitative optoacoustic imaging. Recent efforts are being made in the direction of nontoxic biodegradable contrast agents (such as nanoparticles made of melanin) that are potentially applicable in clinical optoacoustic imaging. In order to increase the efficiency and specificity of contrast agents and probes, they need to be made smart and capable of controlled accumulation in the target cells. This review was written in recognition of the potential breakthroughs in medical optoacoustic imaging that can be enabled by efficient and nontoxic melanin-based optoacoustic contrast agents.

  14. Decoding post-stroke motor function from structural brain imaging

    Directory of Open Access Journals (Sweden)

    Jane M. Rondina

    2016-01-01

    Full Text Available Clinical research based on neuroimaging data has benefited from machine learning methods, which have the ability to provide individualized predictions and to account for the interaction among units of information in the brain. Application of machine learning in structural imaging to investigate diseases that involve brain injury presents an additional challenge, especially in conditions like stroke, due to the high variability across patients regarding characteristics of the lesions. Extracting data from anatomical images in a way that translates brain damage information into features to be used as input to learning algorithms is still an open question. One of the most common approaches to capture regional information from brain injury is to obtain the lesion load per region (i.e. the proportion of voxels in anatomical structures that are considered to be damaged. However, no systematic evaluation has yet been performed to compare this approach with using patterns of voxels (i.e. considering each voxel as a single feature. In this paper we compared both approaches applying Gaussian Process Regression to decode motor scores in 50 chronic stroke patients based solely on data derived from structural MRI. For both approaches we compared different ways to delimit anatomical areas: regions of interest from an anatomical atlas, the corticospinal tract, a mask obtained from fMRI analysis with a motor task in healthy controls and regions selected using lesion-symptom mapping. Our analysis showed that extracting features through patterns of voxels that represent lesion probability produced better results than quantifying the lesion load per region. In particular, from the different ways to delimit anatomical areas compared, the best performance was obtained with a combination of a range of cortical and subcortical motor areas as well as the corticospinal tract. These results will inform the appropriate methodology for predicting long term motor outcomes

  15. Design and Optimization of Gadolinium Based Contrast Agents for Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, G.A.; Geraldes, C.F.G.C. [University of Coimbra (Portugal). Faculty of Science and Technology; University of Coimbra (Portugal). Center of Neurosciences and Cell Biology. Dept. of Biochemistry; E-mail: geraldes@bioq.uc.pt

    2007-07-01

    The role of Gd{sup 3+} chelates as contrast agents in Magnetic Resonance Imaging is discussed. The theory describing the different contributions to paramagnetic relaxation relevant to the understanding of the molecular parameters determining the relativity of those Gd{sup 3+} chelates, is presented. The experimental techniques used to obtain those parameters are also described. Then, the various approaches taken to optimize those parameters, leading to maximum relativity (efficiency) of the contrast agents, are also illustrated with relevant examples taken from the literature. The various types of Gd{sup 3+}-based agents, besides non-specific and hepatobiliary agents, are also discussed, namely blood pool, targeting, responsive and paramagnetic chemical shift saturation transfer (PARACEST) agents. Finally, a perspective is presented of some of the challenges lying ahead in the optimization of MRI contrast agents to be useful in Molecular Imaging. (author)

  16. Mass spectrometry imaging of rat brain lipid profile changes over time following traumatic brain injury.

    Science.gov (United States)

    Roux, Aurelie; Muller, Ludovic; Jackson, Shelley N; Post, Jeremy; Baldwin, Katherine; Hoffer, Barry; Balaban, Carey D; Barbacci, Damon; Schultz, J Albert; Gouty, Shawn; Cox, Brian M; Woods, Amina S

    2016-10-15

    Mild traumatic brain injury (TBI) is a common public health issue that may contribute to chronic degenerative disorders. Membrane lipids play a key role in tissue responses to injury, both as cell signals and as components of membrane structure and cell signaling. This study demonstrates the ability of high resolution mass spectrometry imaging (MSI) to assess sequences of responses of lipid species in a rat controlled cortical impact model for concussion. A matrix of implanted silver nanoparticles was implanted superficially in brain sections for matrix-assisted laser desorption (MALDI) imaging of 50μm diameter microdomains across unfixed cryostat sections of rat brain. Ion-mobility time-of-flight MS was used to analyze and map changes over time in brain lipid composition in a rats after Controlled Cortical Impact (CCI) TBI. Brain MS images showed changes in sphingolipids near the CCI site, including increased ceramides and decreased sphingomyelins, accompanied by changes in glycerophospholipids and cholesterol derivatives. The kinetics differed for each lipid class; for example ceramides increased as early as 1 day after the injury whereas other lipids changes occurred between 3 and 7 days post injury. Silver nanoparticles MALDI matrix is a sensitive new tool for revealing previously undetectable cellular injury response and remodeling in neural, glial and vascular structure of the brain. Lipid biochemical and structural changes after TBI could help highlighting molecules that can be used to determine the severity of such injuries as well as to evaluate the efficacy of potential treatments. Copyright © 2016. Published by Elsevier B.V.

  17. Label-free volumetric optical imaging of intact murine brains

    Science.gov (United States)

    Ren, Jian; Choi, Heejin; Chung, Kwanghun; Bouma, Brett E.

    2017-04-01

    A central effort of today’s neuroscience is to study the brain’s ’wiring diagram’. The nervous system is believed to be a network of neurons interacting with each other through synaptic connection between axons and dendrites, therefore the neuronal connectivity map not only depicts the underlying anatomy, but also has important behavioral implications. Different approaches have been utilized to decipher neuronal circuits, including electron microscopy (EM) and light microscopy (LM). However, these approaches typically demand extensive sectioning and reconstruction for a brain sample. Recently, tissue clearing methods have enabled the investigation of a fully assembled biological system with greatly improved light penetration. Yet, most of these implementations, still require either genetic or exogenous contrast labeling for light microscopy. Here we demonstrate a high-speed approach, termed as Clearing Assisted Scattering Tomography (CAST), where intact brains can be imaged at optical resolution without labeling by leveraging tissue clearing and the scattering contrast of optical frequency domain imaging (OFDI).

  18. Imaging cerebral tryptophan metabolism in brain tumor-associated depression.

    Science.gov (United States)

    Bosnyák, Edit; Kamson, David O; Behen, Michael E; Barger, Geoffrey R; Mittal, Sandeep; Juhász, Csaba

    2015-12-01

    Depression in patients with brain tumors is associated with impaired quality of life and shorter survival. Altered metabolism of tryptophan to serotonin and kynurenine metabolites may play a role in tumor-associated depression. Our recent studies with alpha[(11)C]methyl-L-tryptophan (AMT)-PET in brain tumor patients indicated abnormal tryptophan metabolism not only in the tumor mass but also in normal-appearing contralateral brain. In the present study, we explored if tryptophan metabolism in such brain regions is associated with depression. Twenty-one patients (mean age: 57 years) with a brain tumor (10 meningiomas, 8 gliomas, and 3 brain metastases) underwent AMT-PET scanning. MRI and AMT-PET images were co-registered, and AMT kinetic parameters, including volume of distribution (VD', an estimate of net tryptophan transport) and K (unidirectional uptake, related to tryptophan metabolism), were measured in the tumor mass and in unaffected cortical and subcortical regions contralateral to the tumor. Depression scores (based on the Beck Depression Inventory-II [BDI-II]) were correlated with tumor size, grade, type, and AMT-PET variables. The mean BDI-II score was 12 ± 10 (range: 2-33); clinical levels of depression were identified in seven patients (33 %). High BDI-II scores were most strongly associated with high thalamic AMT K values both in the whole group (Spearman's rho = 0.63, p = 0.004) and in the subgroup of 18 primary brain tumors (r = 0.68, p = 0.004). Frontal and striatal VD' values were higher in the depressed subgroup than in non-depressed patients (p Tumor size, grade, and tumor type were not related to depression scores. Abnormalities of tryptophan transport and metabolism in the thalamus, striatum, and frontal cortex, measured by PET, are associated with depression in patients with brain tumor. These changes may indicate an imbalance between the serotonin and kynurenine pathways and serve as a molecular imaging marker of

  19. Electricity and Magnetism: Insights into the brain from multimodal imaging.

    Science.gov (United States)

    Cohen, M S

    2009-11-01

    The windows into brain function given us by the instruments of neuroimaging each are murky and their view is limited. Simultaneous collection of data from multiple modalities offers the potential to overcome the weaknesses of any tool alone. We argue that the combination of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) offers observations - and hypothesis testing - not possible using either single instrument. Because of their safety profiles and their non-invasive natures, EEG fMRI are among the best available devices for the study of human brain. These methods are complementary. EEG is fast, operating in a time domain comparable to single unit activity, but its localizing power is poor and the field of view is limited. While fMRI has the highest spatial resolution of any noninvasive imaging method and can reveal multiple centers of brain activity implicated in cognitive tasks, it is very slow compared to mental activity and is a poor choice for studying rapidly evolving processes. Here, we address theoretical models of the coupling between EEG and fMRI signals based on cellular physiology and energetics and argue that both tools observe principally synaptic activity. We discuss the technical problems of mutual interference then present several models of brain rhythms for which the joint EEG and fMRI observations provide significant evidence.

  20. PET/SPECT imaging: From carotid vulnerability to brain viability

    Energy Technology Data Exchange (ETDEWEB)

    Meerwaldt, Robbert [Department of Surgery, Isala Clinics, Zwolle (Netherlands); Slart, Riemer H.J.A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Dam, Gooitzen M. van [Department of Surgery, University Medical Center Groningen, Groningen (Netherlands); Luijckx, Gert-Jan [Department of Neurology, University Medical Center Groningen, Groningen (Netherlands); Tio, Rene A. [Department of Cardiology, University Medical Center Groningen, Groningen (Netherlands); Zeebregts, Clark J. [Department of Surgery, University Medical Center Groningen, Groningen (Netherlands)], E-mail: czeebregts@hotmail.com

    2010-04-15

    Background: Current key issues in ischemic stroke are related to carotid plaque vulnerability, brain viability, and timing of intervention. The treatment of ischemic stroke has evolved into urgent active interventions, as 'time is brain'. Functional imaging such as positron emission tomography (PET)/single photon emission computed tomography (SPECT) could improve selection of patients with a vulnerable plaque and evaluation of brain viability in ischemic stroke. Objective: To describe the current applications of PET and SPECT as a diagnostic tool in relation to ischemic stroke. Methods: A literature search using PubMed identified articles. Manual cross-referencing was also performed. Results: Several papers, all observational studies, identified PET/SPECT to be used as a tool to monitor systemic atheroma modifying treatment and to select high-risk patients for surgery regardless of the degree of luminal stenosis in carotid lesions. Furthermore, PET/SPECT is able to quantify the penumbra region during ischemic stroke and in this way may identify those patients who may benefit from timely intervention. Discussion: Functional imaging modalities such as PET/SPECT may become important tools for risk-assessment and evaluation of treatment strategies in carotid plaque vulnerability and brain viability. Prospective clinical studies are needed to evaluate the diagnostic accuracy of PET/SPECT.

  1. The Center for Integrated Molecular Brain Imaging (Cimbi) database

    DEFF Research Database (Denmark)

    Knudsen, Gitte M.; Jensen, Peter S.; Erritzoe, David

    2016-01-01

    We here describe a multimodality neuroimaging containing data from healthy volunteers and patients, acquired within the Lundbeck Foundation Center for Integrated Molecular Brain Imaging (Cimbi) in Copenhagen, Denmark. The data is of particular relevance for neurobiological research questions rela...... currently contains blood and in some instances saliva samples from about 500 healthy volunteers and 300 patients with e.g., major depression, dementia, substance abuse, obesity, and impulsive aggression. Data continue to be added to the Cimbi database and biobank....

  2. A Technique for the Deidentification of Structural Brain MR Images

    Science.gov (United States)

    Bischoff-Grethe, Amanda; Ozyurt, I. Burak; Busa, Evelina; Quinn, Brian T.; Fennema-Notestine, Christine; Clark, Camellia P.; Morris, Shaunna; Bondi, Mark W.; Jernigan, Terry L.; Dale, Anders M.; Brown, Gregory G.; Fischl, Bruce

    2008-01-01

    Due to the increasing need for subject privacy, the ability to deidentify structural MR images so that they do not provide full facial detail is desirable. A program was developed that uses models of nonbrain structures for removing potentially identifying facial features. When a novel image is presented, the optimal linear transform is computed for the input volume (Fischl et al. [2002]: Neuron 33:341–355; Fischl et al. [2004]: Neuroimage 23 (Suppl 1):S69–S84). A brain mask is constructed by forming the union of all voxels with nonzero probability of being brain and then morphologically dilated. All voxels outside the mask with a nonzero probability of being a facial feature are set to 0. The algorithm was applied to 342 datasets that included two different T1-weighted pulse sequences and four different diagnoses (depressed, Alzheimer’s, and elderly and young control groups). Visual inspection showed none had brain tissue removed. In a detailed analysis of the impact of defacing on skull-stripping, 16 datasets were bias corrected with N3 (Sled et al. [1998]: IEEE Trans Med Imaging 17:87–97), defaced, and then skull-stripped using either a hybrid watershed algorithm (Ségonne et al. [2004]: Neuroimage 22:1060–1075, in FreeSurfer) or Brain Surface Extractor (Sandor and Leahy [1997]: IEEE Trans Med Imaging 16:41–54; Shattuck et al. [2001]: Neuroimage 13:856–876); defacing did not appreciably influence the outcome of skull-stripping. Results suggested that the automatic defacing algorithm is robust, efficiently removes nonbrain tissue, and does not unduly influence the outcome of the processing methods utilized; in some cases, skull-stripping was improved. Analyses support this algorithm as a viable method to allow data sharing with minimal data alteration within large-scale multisite projects. PMID:17295313

  3. PANDA: a pipeline toolbox for analyzing brain diffusion images

    Directory of Open Access Journals (Sweden)

    Zaixu eCui

    2013-02-01

    Full Text Available Diffusion magnetic resonance imaging (dMRI is widely used in both scientific research and clinical practice in in-vivo studies of the human brain. While a number of post-processing packages have been developed, fully automated processing of dMRI datasets remains challenging. Here, we developed a MATLAB toolbox named Pipeline for Analyzing braiN Diffusion imAges (PANDA for fully automated processing of brain diffusion images. The processing modules of a few established packages, including FMRIB Software Library (FSL, Pipeline System for Octave and Matlab (PSOM, Diffusion Toolkit and MRIcron, were employed in PANDA. Using any number of raw dMRI datasets from different subjects, in either DICOM or NIfTI format, PANDA can automatically perform a series of steps to process DICOM/NIfTI to diffusion metrics (e.g., FA and MD that are ready for statistical analysis at the voxel-level, the atlas-level and the Tract-Based Spatial Statistics (TBSS-level and can finish the construction of anatomical brain networks for all subjects. In particular, PANDA can process different subjects in parallel, using multiple cores either in a single computer or in a distributed computing environment, thus greatly reducing the time cost when dealing with a large number of datasets. In addition, PANDA has a friendly graphical user interface (GUI, allowing the user to be interactive and to adjust the input/output settings, as well as the processing parameters. As an open-source package, PANDA is freely available at http://www.nitrc.org/projects/panda/. This novel toolbox is expected to substantially simplify the image processing of dMRI datasets and facilitate human structural connectome studies.

  4. PANDA: a pipeline toolbox for analyzing brain diffusion images.

    Science.gov (United States)

    Cui, Zaixu; Zhong, Suyu; Xu, Pengfei; He, Yong; Gong, Gaolang

    2013-01-01

    Diffusion magnetic resonance imaging (dMRI) is widely used in both scientific research and clinical practice in in-vivo studies of the human brain. While a number of post-processing packages have been developed, fully automated processing of dMRI datasets remains challenging. Here, we developed a MATLAB toolbox named "Pipeline for Analyzing braiN Diffusion imAges" (PANDA) for fully automated processing of brain diffusion images. The processing modules of a few established packages, including FMRIB Software Library (FSL), Pipeline System for Octave and Matlab (PSOM), Diffusion Toolkit and MRIcron, were employed in PANDA. Using any number of raw dMRI datasets from different subjects, in either DICOM or NIfTI format, PANDA can automatically perform a series of steps to process DICOM/NIfTI to diffusion metrics [e.g., fractional anisotropy (FA) and mean diffusivity (MD)] that are ready for statistical analysis at the voxel-level, the atlas-level and the Tract-Based Spatial Statistics (TBSS)-level and can finish the construction of anatomical brain networks for all subjects. In particular, PANDA can process different subjects in parallel, using multiple cores either in a single computer or in a distributed computing environment, thus greatly reducing the time cost when dealing with a large number of datasets. In addition, PANDA has a friendly graphical user interface (GUI), allowing the user to be interactive and to adjust the input/output settings, as well as the processing parameters. As an open-source package, PANDA is freely available at http://www.nitrc.org/projects/panda/. This novel toolbox is expected to substantially simplify the image processing of dMRI datasets and facilitate human structural connectome studies.

  5. Nonrigid brain MR image registration using uniform spherical region descriptor.

    Science.gov (United States)

    Liao, Shu; Chung, Albert C S

    2012-01-01

    There are two main issues that make nonrigid image registration a challenging task. First, voxel intensity similarity may not be necessarily equivalent to anatomical similarity in the image correspondence searching process. Second, during the imaging process, some interferences such as unexpected rotations of input volumes and monotonic gray-level bias fields can adversely affect the registration quality. In this paper, a new feature-based nonrigid image registration method is proposed. The proposed method is based on a new type of image feature, namely, uniform spherical region descriptor (USRD), as signatures for each voxel. The USRD is rotation and monotonic gray-level transformation invariant and can be efficiently calculated. The registration process is therefore formulated as a feature matching problem. The USRD feature is integrated with the Markov random field labeling framework in which energy function is defined for registration. The energy function is then optimized by the α-expansion algorithm. The proposed method has been compared with five state-of-the-art registration approaches on both the simulated and real 3-D databases obtained from the BrainWeb and Internet Brain Segmentation Repository, respectively. Experimental results demonstrate that the proposed method can achieve high registration accuracy and reliable robustness behavior.

  6. The impact of "omic" and imaging technologies on assessing the host immune response to biodefence agents

    National Research Council Canada - National Science Library

    Tree, Julia A; Flick-Smith, Helen; Elmore, Michael J; Rowland, Caroline A

    2014-01-01

    ...; and biophotonic imaging for visualising the infectious disease process. All of these technologies hold great promise for important breakthroughs in the rational development of vaccines and therapeutics for biodefence agents.

  7. Imaging synaptic density in the living human brain.

    Science.gov (United States)

    Finnema, Sjoerd J; Nabulsi, Nabeel B; Eid, Tore; Detyniecki, Kamil; Lin, Shu-Fei; Chen, Ming-Kai; Dhaher, Roni; Matuskey, David; Baum, Evan; Holden, Daniel; Spencer, Dennis D; Mercier, Joël; Hannestad, Jonas; Huang, Yiyun; Carson, Richard E

    2016-07-20

    Chemical synapses are the predominant neuron-to-neuron contact in the central nervous system. Presynaptic boutons of neurons contain hundreds of vesicles filled with neurotransmitters, the diffusible signaling chemicals. Changes in the number of synapses are associated with numerous brain disorders, including Alzheimer's disease and epilepsy. However, all current approaches for measuring synaptic density in humans require brain tissue from autopsy or surgical resection. We report the use of the synaptic vesicle glycoprotein 2A (SV2A) radioligand [(11)C]UCB-J combined with positron emission tomography (PET) to quantify synaptic density in the living human brain. Validation studies in a baboon confirmed that SV2A is an alternative synaptic density marker to synaptophysin. First-in-human PET studies demonstrated that [(11)C]UCB-J had excellent imaging properties. Finally, we confirmed that PET imaging of SV2A was sensitive to synaptic loss in patients with temporal lobe epilepsy. Thus, [(11)C]UCB-J PET imaging is a promising approach for in vivo quantification of synaptic density with several potential applications in diagnosis and therapeutic monitoring of neurological and psychiatric disorders. Copyright © 2016, American Association for the Advancement of Science.

  8. Multi-Agent Control for Autonomous, Real-time and Choreographic Image Display

    OpenAIRE

    Alonso Mora, Javier

    2009-01-01

    This thesis presents a new way of looking at images and videos, Display Swarm, which is a novel robot display providing new types of visual experience. This work is focused on creating a multi-agent control method for real-time, autonomous and choreographic image display, where each pixel of an image is a mobile robot. This robot display consists of a large number of small autonomous agents, each one representing a pixel of the image, and aims at the generation of aesthetic eff...

  9. Harmonic chirp imaging method for ultrasound contrast agent

    NARCIS (Netherlands)

    Borsboom, Jerome M.G.; Chin, Chien Ting; Bouakaz, Ayache; Versluis, Michel; de Jong, N.

    2005-01-01

    Coded excitation is currently used in medical ultrasound to increase signal-to-noise ratio (SNR) and penetration depth. We propose a chirp excitation method for contrast agents using the second harmonic component of the response. This method is based on a compression filter that selectively

  10. Ultrasound imaging and contrast agents: a safe alternative to MRI?

    NARCIS (Netherlands)

    Wink, Margot H.; Wijkstra, Hessel; de La Rosette, Jean J. M. C. H.; Grimbergen, Cornelis A.

    2006-01-01

    Microbubble contrast media are used to enhance ultrasound images. Because ultrasound is a real-time investigation, contrast-enhanced ultrasound offers possibilities for perfusion imaging. This review is conducted to evaluate the safety of contrast-enhanced ultrasound and its possible role in medical

  11. Comparative assessments of the effects of alcohol exposure on fetal brain development using optical coherence tomography and ultrasound imaging

    Science.gov (United States)

    Sudheendran, Narendran; Bake, Shameena; Miranda, Rajesh C.; Larin, Kirill V.

    2013-02-01

    The developing fetal brain is vulnerable to a variety of environmental agents including maternal ethanol consumption. Preclinical studies on the development and amelioration of fetal teratology would be significantly facilitated by the application of high resolution imaging technologies like optical coherence tomography (OCT) and high-frequency ultrasound (US). This study investigates the ability of these imaging technologies to measure the effects of maternal ethanol exposure on brain development, ex vivo, in fetal mice. Pregnant mice at gestational day 12.5 were administered ethanol (3 g/Kg b.wt.) or water by intragastric gavage, twice daily for three consecutive days. On gestational day 14.5, fetuses were collected and imaged. Three-dimensional images of the mice fetus brains were obtained by OCT and high-resolution US, and the volumes of the left and right ventricles of the brain were measured. Ethanol-exposed fetuses exhibited a statistically significant, 2-fold increase in average left and right ventricular volumes compared with the ventricular volume of control fetuses, with OCT-derived measures of 0.38 and 0.18 mm3, respectively, whereas the boundaries of the fetal mouse lateral ventricles were not clearly definable with US imaging. Our results indicate that OCT is a useful technology for assessing ventriculomegaly accompanying alcohol-induced developmental delay. This study clearly demonstrated advantages of using OCT for quantitative assessment of embryonic development compared with US imaging.

  12. Ions doped melanin nanoparticle as a multiple imaging agent.

    Science.gov (United States)

    Ha, Shin-Woo; Cho, Hee-Sang; Yoon, Young Il; Jang, Moon-Sun; Hong, Kwan Soo; Hui, Emmanuel; Lee, Jung Hee; Yoon, Tae-Jong

    2017-10-10

    Multimodal nanomaterials are useful for providing enhanced diagnostic information simultaneously for a variety of in vivo imaging methods. According to our research findings, these multimodal nanomaterials offer promising applications for cancer therapy. Melanin nanoparticles can be used as a platform imaging material and they can be simply produced by complexation with various imaging active ions. They are capable of specifically targeting epidermal growth factor receptor (EGFR)-expressing cancer cells by being anchored with a specific antibody. Ion-doped melanin nanoparticles were found to have high bioavailability with long-term stability in solution, without any cytotoxicity in both in vitro and in vivo systems. By combining different imaging modalities with melanin particles, we can use the complexes to obtain faster diagnoses by computed tomography deep-body imaging and greater detailed pathological diagnostic information by magnetic resonance imaging. The ion-doped melanin nanoparticles also have applications for radio-diagnostic treatment and radio imaging-guided surgery, warranting further proof of concept experimental.

  13. Molecular Imaging of the Brain Using Multi-Quantum Coherence and Diagnostics of Brain Disorders

    CERN Document Server

    Kaila, M M

    2013-01-01

    This book examines multi-quantum magnetic resonance imaging methods and the diagnostics of brain disorders. It consists of two Parts. The part I is initially devoted towards the basic concepts of the conventional single quantum MRI techniques. It is supplemented by the basic knowledge required to understand multi-quantum MRI. Practical illustrations are included both on recent developments in conventional MRI and the MQ-MRI. This is to illustrate the connection between theoretical concepts and their scope in the clinical applications. The Part II initially sets out the basic details about quadrupole charge distribution present in certain nuclei and their importance about the functions they perform in our brain. Some simplified final mathematical expressions are included to illustrate facts about the basic concepts of the quantum level interactions between magnetic dipole and the electric quadrupole behavior of useful nuclei present in the brain. Selected practical illustrations, from research and clinical pra...

  14. Carbon nanomaterials: multi-functional agents for biomedical fluorescence and Raman imaging.

    Science.gov (United States)

    Bartelmess, J; Quinn, S J; Giordani, S

    2015-07-21

    Carbon based nanomaterials have emerged over the last few years as important agents for biomedical fluorescence and Raman imaging applications. These spectroscopic techniques utilize either fluorescently labelled carbon nanomaterials or the intrinsic photophysical properties of the carbon nanomaterial. In this review article we present the utilization and performance of several classes of carbon nanomaterials, namely carbon nanotubes, carbon nanohorns, carbon nanoonions, nanodiamonds and different graphene derivatives, which are currently employed for in vitro as well as in vivo imaging in biology and medicine. A variety of different approaches, imaging agents and techniques are examined and the specific properties of the various carbon based imaging agents are discussed. Some theranostic carbon nanomaterials, which combine diagnostic features (i.e. imaging) with cell specific targeting and therapeutic approaches (i.e. drug delivery or photothermal therapy), are also included in this overview.

  15. Phase-change contrast agents for imaging and therapy.

    Science.gov (United States)

    Sheeran, Paul S; Dayton, Paul A

    2012-01-01

    Phase-change contrast agents (PCCAs) for ultrasound-based applications have resulted in novel ways of approaching diagnostic and therapeutic techniques beyond what is possible with microbubble contrast agents and liquid emulsions. When subjected to sufficient pressures delivered by an ultrasound transducer, stabilized droplets undergo a phase-transition to the gaseous state and a volumetric expansion occurs. This phenomenon, termed acoustic droplet vaporization, has been proposed as a means to address a number of in vivo applications at the microscale and nanoscale. In this review, the history of PCCAs, physical mechanisms involved, and proposed applications are discussed with a summary of studies demonstrated in vivo. Factors that influence the design of PCCAs are discussed, as well as the need for future studies to characterize potential bioeffects for administration in humans and optimization of ultrasound parameters.

  16. A Novel Polyacrylamide Magnetic Nanoparticle Contrast Agent for Molecular Imaging using MRI

    Directory of Open Access Journals (Sweden)

    Bradford A. Moffat

    2003-10-01

    Full Text Available A novel Polyacrylamide superparamagnetic iron oxide nanoparticle platform is described which has been synthetically prepared such that multiple crystals of iron oxide are encapsulated within a single Polyacrylamide matrix (PolyAcrylamide Magnetic [PAM] nanoparticles. This formulation provides for an extremely large T2 and T2* relaxivity of between 620 and 1140 sec−1 mM−1. Administration of PAM nanoparticles into rats bearing orthotopic 9L gliomas allowed quantitative pharmacokinetic analysis of the uptake of nanoparticles in the vasculature, brain, and glioma. Addition of polyethylene glycol of varying sizes (0.6, 2, and 10 kDa to the surface of the PAM nanoparticles resulted in an increase in plasma half-life and affected tumor uptake and retention of the nanoparticles as quantified by changes in tissue contrast using MRI. The flexible formulation of these nanoparticles suggests that future modifications could be accomplished allowing for their use as a targeted molecular imaging contrast agent and/or therapeutic platform for multiple indications.

  17. Automated delineation of stroke lesions using brain CT images

    Directory of Open Access Journals (Sweden)

    Céline R. Gillebert

    2014-01-01

    Full Text Available Computed tomographic (CT images are widely used for the identification of abnormal brain tissue following infarct and hemorrhage in stroke. Manual lesion delineation is currently the standard approach, but is both time-consuming and operator-dependent. To address these issues, we present a method that can automatically delineate infarct and hemorrhage in stroke CT images. The key elements of this method are the accurate normalization of CT images from stroke patients into template space and the subsequent voxelwise comparison with a group of control CT images for defining areas with hypo- or hyper-intense signals. Our validation, using simulated and actual lesions, shows that our approach is effective in reconstructing lesions resulting from both infarct and hemorrhage and yields lesion maps spatially consistent with those produced manually by expert operators. A limitation is that, relative to manual delineation, there is reduced sensitivity of the automated method in regions close to the ventricles and the brain contours. However, the automated method presents a number of benefits in terms of offering significant time savings and the elimination of the inter-operator differences inherent to manual tracing approaches. These factors are relevant for the creation of large-scale lesion databases for neuropsychological research. The automated delineation of stroke lesions from CT scans may also enable longitudinal studies to quantify changes in damaged tissue in an objective and reproducible manner.

  18. Novel strategies of Raman imaging for brain tumor research.

    Science.gov (United States)

    Anna, Imiela; Bartosz, Polis; Lech, Polis; Halina, Abramczyk

    2017-10-17

    Raman diagnostics and imaging have been shown to be an effective tool for the analysis and discrimination of human brain tumors from normal structures. Raman spectroscopic methods have potential to be applied in clinical practice as they allow for identification of tumor margins during surgery. In this study, we investigate medulloblastoma (grade IV WHO) (n= 5), low-grade astrocytoma (grades I-II WHO) (n =4), ependymoma (n=3) and metastatic brain tumors (n= 1) and the tissue from the negative margins used as normal controls. We compare a high grade medulloblastoma, low grade astrocytoma and non-tumor samples from human central nervous system (CNS) tissue. Based on the properties of the Raman vibrational features and Raman images we provide a real-time feedback method that is label-free to monitor tumor metabolism that reveals reprogramming of biosynthesis of lipids, proteins, DNA and RNA. Our results indicate marked metabolic differences between low and high grade brain tumors. We discuss molecular mechanisms causing these metabolic changes, particularly lipid alterations in malignant medulloblastoma and low grade gliomas that may shed light on the mechanisms driving tumor recurrence thereby revealing new approaches for the treatment of malignant glioma. We have found that the high-grade tumors of central nervous system (medulloblastoma) exhibit enhanced level of β-sheet conformation and down-regulated level of α-helix conformation when comparing against normal tissue. We have found that almost all tumors studied in the paper have increased Raman signals of nucleic acids. This increase can be interpreted as increased DNA/RNA turnover in brain tumors. We have shown that the ratio of Raman intensities I 2930 /I 2845 at 2930 and 2845 cm -1 is a good source of information on the ratio of lipid and protein contents. We have found that the ratio reflects the different lipid and protein contents of cancerous brain tissue compared to the non-tumor tissue. We found that

  19. Analysis of spatio-temporal brain imaging patterns by Hidden Markov Models and serial MRI images.

    Science.gov (United States)

    Wang, Ying; Resnick, Susan M; Davatzikos, Christos

    2014-09-01

    Brain changes due to development and maturation, normal aging, or degenerative disease are continuous, gradual, and variable across individuals. To quantify the individual progression of brain changes, we propose a spatio-temporal methodology based on Hidden Markov Models (HMM), and apply it on four-dimensional structural brain magnetic resonance imaging series of older individuals. First, regional brain features are extracted in order to reduce image dimensionality. This process is guided by the objective of the study or the specific imaging patterns whose progression is of interest, for example, the evaluation of Alzheimer-like patterns of brain change in normal individuals. These regional features are used in conjunction with HMMs, which aim to measure the dynamic association between brain structure changes and progressive stages of disease over time. A bagging framework is used to obtain models with good generalization capability, since in practice the number of serial scans is limited. An application of the proposed methodology was to detect individuals with the risk of developing MCI, and therefore it was tested on modeling the progression of brain atrophy patterns in older adults. With HMM models, the state-transition paths corresponding to longitudinal brain changes were constructed from two completely independent datasets, the Alzheimer Disease Neuroimaging Initiative and the Baltimore Longitudinal Study of Aging. The statistical analysis of HMM-state paths among the normal, progressive MCI, and MCI groups indicates that, HMM-state index 1 is likely to be a predictor of the conversion from cognitively normal to MCI, potentially many years before clinical symptoms become measurable. Copyright © 2014 Wiley Periodicals, Inc.

  20. Wearable Brain Imaging with Multi-Modal Physiological Recording.

    Science.gov (United States)

    Strangman, Gary E; Ivkovic, Vladimir; Zhang, Quan

    2017-07-13

    The brain is a central component of cognitive and physical human performance. Measures including functional brain activation, cerebral perfusion, cerebral oxygenation, evoked electrical responses, and resting hemodynamic and electrical activity are all related to, or can predict health status or performance decrements. However, measuring brain physiology typically requires large, stationary machines that are not suitable for mobile or self-monitoring. Moreover, when individuals are ambulatory, systemic physiological fluctuations-e.g., in heart rate, blood pressure, skin perfusion and more-can interfere with non-invasive brain measurements. In efforts to address the physiological monitoring and performance assessment needs for astronauts during spaceflight, we have developed easy-to-use, wearable prototypes- NINscan, for near-infrared scanning-that can collect synchronized multi-modal physiology data, including hemodynamic deep-tissue imaging (including brain and muscles), electroencephalography, electrocardiography, electromyography, electrooculography, accelerometry, gyroscopy, pressure, respiration and temperature measurements. Given their self-contained and portable nature, these devices can be deployed in a much broader range of settings-including austere environments-thereby enabling a wider range of novel medical and research physiology applications. We review these, including high-altitude assessments, self-deployable multi-modal e.g., (polysomnographic) recordings in remote or low-resource environments, fluid shifts in variable-gravity or spaceflight analog environments, intra-cranial brain motion during high-impact sports, and long-duration monitoring for clinical symptom-capture in various clinical conditions. In addition to further enhancing sensitivity and miniaturization, advanced computational algorithms could help support real-time feedback and alerts regarding performance and health. Copyright © 2017, Journal of Applied Physiology.

  1. Covalent nano delivery systems for selective imaging and treatment of brain tumors.

    Science.gov (United States)

    Ljubimova, Julia Y; Sun, Tao; Mashouf, Leila; Ljubimov, Alexander V; Israel, Liron L; Ljubimov, Vladimir A; Falahatian, Vida; Holler, Eggehard

    2017-04-01

    Nanomedicine is a rapidly evolving form of therapy that holds a great promise for superior drug delivery efficiency and therapeutic efficacy than conventional cancer treatment. In this review, we attempt to cover the benefits and the limitations of current nanomedicines with special attention to covalent nano conjugates for imaging and drug delivery in the brain. The improvement in brain tumor treatment remains dismal despite decades of efforts in drug development and patient care. One of the major obstacles in brain cancer treatment is the poor drug delivery efficiency owing to the unique blood-brain barrier (BBB) in the CNS. Although various anti-cancer agents are available to treat tumors outside of the CNS, the majority fails to cross the BBB. In this regard, nanomedicines have increasingly drawn attention due to their multi-functionality and versatility. Nano drugs can penetrate BBB and other biological barriers, and selectively accumulate in tumor cells, while concurrently decreasing systemic toxicity. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  2. First in vivo traumatic brain injury imaging via magnetic particle imaging

    Science.gov (United States)

    Orendorff, Ryan; Peck, Austin J.; Zheng, Bo; Shirazi, Shawn N.; Ferguson, R. Matthew; Khandhar, Amit P.; Kemp, Scott J.; Goodwill, Patrick; Krishnan, Kannan M.; Brooks, George A.; Kaufer, Daniela; Conolly, Steven

    2017-05-01

    Emergency room visits due to traumatic brain injury (TBI) is common, but classifying the severity of the injury remains an open challenge. Some subjective methods such as the Glasgow Coma Scale attempt to classify traumatic brain injuries, as well as some imaging based modalities such as computed tomography and magnetic resonance imaging. However, to date it is still difficult to detect and monitor mild to moderate injuries. In this report, we demonstrate that the magnetic particle imaging (MPI) modality can be applied to imaging TBI events with excellent contrast. MPI can monitor injected iron nanoparticles over long time scales without signal loss, allowing researchers and clinicians to monitor the change in blood pools as the wound heals.

  3. Pet Imaging Of The Chemistry Of The Brain

    Science.gov (United States)

    Wagner, Henry N., Jr.

    1986-06-01

    Advances in neurobiology today are as important as the advances in atomic physics at the turn of the century and molecular genetics in the 1950's. Positron-emission tomography is participating in these advances by making it possible for the first time to measure the chemistry of the living human brain in health and disease and to relate the changes at the molecular level to the functioning of the human mind. The amount of data generated requires modern data processing, display, and archiving capabilities. To achieve maximum benefit from the PET imaging and the derived quantitative measurements, the data must be combined with information, usually of a structural nature, from other imaging modalities, chiefly computed tomography and magnetic resonance imaging.

  4. The Multimodal Brain Tumor Image Segmentation Benchmark (BRATS)

    DEFF Research Database (Denmark)

    Menze, Bjoern H.; Jakab, Andras; Bauer, Stefan

    2015-01-01

    In this paper we report the set-up and results of the Multimodal Brain Tumor Image Segmentation Benchmark (BRATS) organized in conjunction with the MICCAI 2012 and 2013 conferences. Twenty state-of-the-art tumor segmentation algorithms were applied to a set of 65 multi-contrast MR scans of low......- and high-grade glioma patients – manually annotated by up to four raters – and to 65 comparable scans generated using tumor image simulation software. Quantitative evaluations revealed considerable disagreement between the human raters in segmenting various tumor sub-regions (Dice scores in the range 74...... a hierarchical majority vote yielded segmentations that consistently ranked above all individual algorithms, indicating remaining opportunities for further methodological improvements. The BRATS image data and manual annotations continue to be publicly available through an online evaluation system as an ongoing...

  5. Simulated driving and brain imaging: combining behavior, brain activity, and virtual reality.

    Science.gov (United States)

    Carvalho, Kara N; Pearlson, Godfrey D; Astur, Robert S; Calhoun, Vince D

    2006-01-01

    Virtual reality in the form of simulated driving is a useful tool for studying the brain. Various clinical questions can be addressed, including both the role of alcohol as a modulator of brain function and regional brain activation related to elements of driving. We reviewed a study of the neural correlates of alcohol intoxication through the use of a simulated-driving paradigm and wished to demonstrate the utility of recording continuous-driving behavior through a new study using a programmable driving simulator developed at our center. Functional magnetic resonance imaging data was collected from subjects while operating a driving simulator. Independent component analysis (ICA) was used to analyze the data. Specific brain regions modulated by alcohol, and relationships between behavior, brain function, and alcohol blood levels were examined with aggregate behavioral measures. Fifteen driving epochs taken from two subjects while also recording continuously recorded driving variables were analyzed with ICA. Preliminary findings reveal that four independent components correlate with various aspects of behavior. An increase in braking while driving was found to increase activation in motor areas, while cerebellar areas showed signal increases during steering maintenance, yet signal decreases during steering changes. Additional components and significant findings are further outlined. In summary, continuous behavioral variables conjoined with ICA may offer new insight into the neural correlates of complex human behavior.

  6. Connecting combat-related mild traumatic brain injury with posttraumatic stress disorder symptoms through brain imaging.

    Science.gov (United States)

    Costanzo, Michelle E; Chou, Yi-Yu; Leaman, Suzanne; Pham, Dzung L; Keyser, David; Nathan, Dominic E; Coughlin, Mary; Rapp, Paul; Roy, Michael J

    2014-08-08

    Mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) may share common symptom and neuropsychological profiles in military service members (SMs) following deployment; while a connection between the two conditions is plausible, the relationship between them has been difficult to discern. The intent of this report is to enhance our understanding of the relationship between findings on structural and functional brain imaging and symptoms of PTSD. Within a cohort of SMs who did not meet criteria for PTSD but were willing to complete a comprehensive assessment within 2 months of their return from combat deployment, we conducted a nested case-control analysis comparing those with combat-related mTBI to age/gender-matched controls with diffusion tensor imaging, resting state functional magnetic resonance imaging and a range of psychological measures. We report degraded white matter integrity in those with a history of combat mTBI, and a positive correlation between the white matter microstructure and default mode network (DMN) connectivity. Higher clinician-administered and self-reported subthreshold PTSD symptoms were reported in those with combat mTBI. Our findings offer a potential mechanism through which mTBI may alter brain function, and in turn, contribute to PTSD symptoms. Published by Elsevier Ireland Ltd.

  7. Polypyrrole Hollow Microspheres as Echogenic Photothermal Agent for Ultrasound Imaging Guided Tumor Ablation

    Science.gov (United States)

    Zha, Zhengbao; Wang, Jinrui; Qu, Enze; Zhang, Shuhai; Jin, Yushen; Wang, Shumin; Dai, Zhifei

    2013-01-01

    Ultrasound (US) imaging provides a valuable opportunity to administer photothermal therapy (PTT) of cancer with real-time guidance to ensure proper targeting, but only a few theranostic agents were developed by physically grafting near infrared (NIR)-absorbing inorganic nanomaterials to ready-made ultrasound contrast agents (UCAs) for US imaging guided PTT. In this paper, NIR absorbing hollow microspheres were generated from polypyrrole merely using a facile one-step microemulsion method. It was found that the obtained polypyrrole hollow microspheres (PPyHMs) can act as an efficient theranostic agent not only to enhance US imaging greatly, but also exhibit excellent photohyperthermic effects. The contrast consistently sustained the echo signals for no less than 5 min and the NIR laser light ablated the tumor completely within two weeks in the presence of PPyHMs. More importantly, no use of additional NIR absorber substantially minimizes an onetime dose of the theranostic agent. PMID:23912977

  8. Diffusion Tensor Imaging Of the Brain in Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Jo Ann V. Antenor-Dorsey

    2014-10-01

    Full Text Available Individuals with Type 1 diabetes mellitus (T1DM are required to carefully manage their insulin dosing, dietary intake, and activity levels in order to maintain optimal blood sugar levels. Over time, exposure to hyperglycaemia is known to cause significant damage to the peripheral nervous system, but its impact on the central nervous system has been less well studied. Researchers have begun to explore the cumulative impact of commonly experienced blood glucose fluctuations on brain structure and function in patient populations. To date, these studies have typically used magnetic resonance imaging to measure regional grey and white matter volumes across the brain. However, newer methods, such as diffusion tensor imaging (DTI can measure the microstructural properties of white matter, which can be more sensitive to neurological effects than standard volumetric measures. Studies are beginning to use DTI to understand the impact of T1DM on white matter structure in the human brain. This work, its implications, future directions, and important caveats, are the focus of this review.

  9. The clinical utility of brain SPECT imaging in process addictions.

    Science.gov (United States)

    Amen, Daniel G; Willeumier, Kristen; Johnson, Robert

    2012-01-01

    Brain SPECT imaging is a nuclear medicine study that uses isotopes bound to neurospecific pharmaceuticals to evaluate regional cerebral blood flow (rCBF) and indirectly metabolic activity. With current available technology and knowledge SPECT has the potential to add important clinical information to benefit patient care in many different areas of a substance abuse practice, including in the area of process addictions. This article explores the ways brain SPECT has the potential to be useful to clinicians in helping to understand and direct treatment for complex cases of obesity and sexual addictions. Areas where SPECT can add value include helping clinicians ask betterquestions, helping them in making more complete diagnoses, evaluating underlying brain systems pathology, decreasing stigma and increasing compliance, and visualizing effectiveness via follow-up evaluations. In particular, SPECT can help in identifying and assessing the issue of brain trauma and toxicity in process addictions, which may be significant contributing factors in treatment failure. Three illustrative case histories will be given.

  10. Metal complex-based templates and nanostructures for magnetic resonance/optical multimodal imaging agents

    NARCIS (Netherlands)

    Galindo Millan, Jealemy

    2012-01-01

    In this thesis, new approaches directed towards simple and functional imaging agents (IAs) for magnetic resonance (MR) and fluorescence multimodal imaging are proposed. In Chapter 3, hybrid silver nanostructures (hAgNSs), grown using a polyamino carboxylic acid scaffold, namely

  11. Imaging of brain oxygenation with magnetic resonance imaging: A validation with positron emission tomography in the healthy and tumoural brain.

    Science.gov (United States)

    Valable, Samuel; Corroyer-Dulmont, Aurélien; Chakhoyan, Ararat; Durand, Lucile; Toutain, Jérôme; Divoux, Didier; Barré, Louisa; MacKenzie, Eric T; Petit, Edwige; Bernaudin, Myriam; Touzani, Omar; Barbier, Emmanuel L

    2017-07-01

    The partial pressure in oxygen remains challenging to map in the brain. Two main strategies exist to obtain surrogate measures of tissue oxygenation: the tissue saturation studied by magnetic resonance imaging (S t O 2 -MRI) and the identification of hypoxia by a positron emission tomography (PET) biomarker with 3-[ 18 F]fluoro-1-(2-nitro-1-imidazolyl)-2-propanol ([ 18 F]-FMISO) as the leading radiopharmaceutical. Nonetheless, a formal validation of S t O 2 -MRI against FMISO-PET has not been performed. The objective of our studies was to compare the two approaches in (a) the normal rat brain when the rats were submitted to hypoxemia; (b) animals implanted with four tumour types differentiated by their oxygenation. Rats were submitted to normoxic and hypoxemic conditions. For the brain tumour experiments, U87-MG, U251-MG, 9L and C6 glioma cells were orthotopically inoculated in rats. For both experiments, S t O 2 -MRI and [ 18 F]-FMISO PET were performed sequentially. Under hypoxemia conditions, S t O 2 -MRI revealed a decrease in oxygen saturation in the brain. Nonetheless, [ 18 F]-FMISO PET, pimonidazole immunohistochemistry and molecular biology were insensitive to hypoxia. Within the context of tumours, S t O 2 -MRI was able to detect hypoxia in the hypoxic models, mimicking [ 18 F]-FMISO PET with high sensitivity/specificity. Altogether, our data clearly support that, in brain pathologies, S t O 2 -MRI could be a robust and specific imaging biomarker to assess hypoxia.

  12. Semi-automatic Epileptic Hot Spot Detection in ECD brain SPECT images

    Science.gov (United States)

    Papp, Laszlo; Zuhayra, Maaz; Henze, Eberhard

    A method is proposed to process ECD brain SPECT images representing epileptic hot spots inside the brain. For validation 35 ictal —interictal patient image data were processed. The images were registered by a normalized mutual information method, then the separation of the suspicious and normal brain areas were performed by two threshold-based segmentations. Normalization between the images was performed by local normal brain mean values. Based on the validation made by two medical physicians, minimal human intervention in the segmentation parameters was necessary to detect all epileptic spots and minimize the number of false spots inside the brain.

  13. Evaluation of a 99Tcm bound brain scanning agent for single photon emission computed tomography

    DEFF Research Database (Denmark)

    Andersen, A R; Hasselbalch, S G; Paulson, O B

    1986-01-01

    D,L HM-PAO-99Tcm (PAO) is a lipophilic tracer complex which is avidly taken up by the brain. We have compared the regional distribution of PAO with regional cerebral blood flow (CBF). CBF was measured by single photon emission computed tomography (SPECT) by Tomomatic 64 after 133Xe inhalation in 41...... patients. With the same SPECT the distribution of PAO was measured after intravenous injection. High resolution (HR) and low resolution (LR) studies were performed yielding a resolution of 6-10 mm (HR) and 15-20 mm (LR). PAO images showed close resemblance to 133Xe CBF tomograms. Only 20 per cent...

  14. Pulsed laser diode photoacoustic tomography (PLD-PAT) system for fast in vivo imaging of small animal brain

    Science.gov (United States)

    Upputuri, Paul Kumar; Kalva, Sandeep Kumar; Moothanchery, Mohesh; Pramanik, Manojit

    2017-03-01

    In recent years, high-repetition rate pulsed laser diode (PLD) was used as an alternative to the Nd:YAG lasers for photoacoustic tomography (PAT). The use of PLD makes the overall PAT system, a low-cost, portable, and high frame rate imaging tool for preclinical applications. In this work, we will present a portable in vivo pulsed laser diode based photoacoustic tomography (PLD-PAT) system. The PLD is integrated inside a circular scanning geometry. The PLD can provide near-infrared ( 803 nm) pulses with pulse duration 136 ns, and pulse energy 1.4 mJ / pulse at 7 kHz repetition rate. The system will be demonstrated for in vivo fast imaging of small animal brain. To enhance the contrast of brain imaging, experiments will be carried out using contrast agents which have strong absorption around laser excitation wavelength. This low-cost, portable small animal brain imaging system could be very useful for brain tumor imaging and therapy.

  15. Development of magneto-plasmonic nanoparticles for multimodal image-guided therapy to the brain.

    Science.gov (United States)

    Tomitaka, Asahi; Arami, Hamed; Raymond, Andrea; Yndart, Adriana; Kaushik, Ajeet; Jayant, Rahul Dev; Takemura, Yasushi; Cai, Yong; Toborek, Michal; Nair, Madhavan

    2017-01-05

    Magneto-plasmonic nanoparticles are one of the emerging multi-functional materials in the field of nanomedicine. Their potential for targeting and multi-modal imaging is highly attractive. In this study, magnetic core/gold shell (MNP@Au) magneto-plasmonic nanoparticles were synthesized by citrate reduction of Au ions on magnetic nanoparticle seeds. Hydrodynamic size and optical properties of magneto-plasmonic nanoparticles synthesized with the variation of Au ions and reducing agent concentrations were evaluated. The synthesized magneto-plasmonic nanoparticles exhibited superparamagnetic properties, and their magnetic properties contributed to the concentration-dependent contrast in magnetic resonance imaging (MRI). The imaging contrast from the gold shell part of the magneto-plasmonic nanoparticles was also confirmed by X-ray computed tomography (CT). The transmigration study of the magneto-plasmonic nanoparticles using an in vitro blood-brain barrier (BBB) model proved enhanced transmigration efficiency without disrupting the integrity of the BBB, and showed potential to be used for brain diseases and neurological disorders.

  16. Lactoferrin conjugated iron oxide nanoparticles for targeting brain glioma cells in magnetic particle imaging

    Science.gov (United States)

    Tomitaka, Asahi; Arami, Hamed; Gandhi, Sonu; Krishnan, Kannan M.

    2015-10-01

    Magnetic Particle Imaging (MPI) is a new real-time imaging modality, which promises high tracer mass sensitivity and spatial resolution directly generated from iron oxide nanoparticles. In this study, monodisperse iron oxide nanoparticles with median core diameters ranging from 14 to 26 nm were synthesized and their surface was conjugated with lactoferrin to convert them into brain glioma targeting agents. The conjugation was confirmed with the increase of the hydrodynamic diameters, change of zeta potential, and Bradford assay. Magnetic particle spectrometry (MPS), performed to evaluate the MPI performance of these nanoparticles, showed no change in signal after lactoferrin conjugation to nanoparticles for all core diameters, suggesting that the MPI signal is dominated by Néel relaxation and thus independent of hydrodynamic size difference or presence of coating molecules before and after conjugations. For this range of core sizes (14-26 nm), both MPS signal intensity and spatial resolution improved with increasing core diameter of nanoparticles. The lactoferrin conjugated iron oxide nanoparticles (Lf-IONPs) showed specific cellular internalization into C6 cells with a 5-fold increase in MPS signal compared to IONPs without lactoferrin, both after 24 h incubation. These results suggest that Lf-IONPs can be used as tracers for targeted brain glioma imaging using MPI.

  17. Functional connectivity of the rodent brain using optical imaging

    Science.gov (United States)

    Guevara Codina, Edgar

    The aim of this thesis is to apply functional connectivity in a variety of animal models, using several optical imaging modalities. Even at rest, the brain shows high metabolic activity: the correlation in slow spontaneous fluctuations identifies remotely connected areas of the brain; hence the term "functional connectivity". Ongoing changes in spontaneous activity may provide insight into the neural processing that takes most of the brain metabolic activity, and so may provide a vast source of disease related changes. Brain hemodynamics may be modified during disease and affect resting-state activity. The thesis aims to better understand these changes in functional connectivity due to disease, using functional optical imaging. The optical imaging techniques explored in the first two contributions of this thesis are Optical Imaging of Intrinsic Signals and Laser Speckle Contrast Imaging, together they can estimate the metabolic rate of oxygen consumption, that closely parallels neural activity. They both have adequate spatial and temporal resolution and are well adapted to image the convexity of the mouse cortex. In the last article, a depth-sensitive modality called photoacoustic tomography was used in the newborn rat. Optical coherence tomography and laminar optical tomography were also part of the array of imaging techniques developed and applied in other collaborations. The first article of this work shows the changes in functional connectivity in an acute murine model of epileptiform activity. Homologous correlations are both increased and decreased with a small dependence on seizure duration. These changes suggest a potential decoupling between the hemodynamic parameters in resting-state networks, underlining the importance to investigate epileptic networks with several independent hemodynamic measures. The second study examines a novel murine model of arterial stiffness: the unilateral calcification of the right carotid. Seed-based connectivity analysis

  18. Level set method coupled with Energy Image features for brain MR image segmentation.

    Science.gov (United States)

    Punga, Mirela Visan; Gaurav, Rahul; Moraru, Luminita

    2014-06-01

    Up until now, the noise and intensity inhomogeneity are considered one of the major drawbacks in the field of brain magnetic resonance (MR) image segmentation. This paper introduces the energy image feature approach for intensity inhomogeneity correction. Our approach of segmentation takes the advantage of image features and preserves the advantages of the level set methods in region-based active contours framework. The energy image feature represents a new image obtained from the original image when the pixels' values are replaced by local energy values computed in the 3×3 mask size. The performance and utility of the energy image features were tested and compared through two different variants of level set methods: one as the encompassed local and global intensity fitting method and the other as the selective binary and Gaussian filtering regularized level set method. The reported results demonstrate the flexibility of the energy image feature to adapt to level set segmentation framework and to perform the challenging task of brain lesion segmentation in a rather robust way.

  19. Characterisation of Lesions after Stereotactic Radiosurgery for Brain Metastases: Impact of Delayed Contrast Magnetic Resonance Imaging.

    Science.gov (United States)

    Wagner, S; Gufler, H; Eichner, G; Lanfermann, H

    2017-03-01

    To investigate if brain metastases and radiation injuries after stereotactic radiosurgery (SRS) have different signal intensity (SI) time courses up to 55 min after contrast agent application and if delayed contrast magnetic resonance imaging (MRI) contributes to improve diagnostic accuracy. Thirty-four consecutive patients treated with SRS for cerebral metastases were prospectively enrolled in the study. T1-weighted images were acquired on a 3-Tesla MR unit at three time points, at 2 (TP1), 15 (TP2) and 55 (TP3) min after administering contrast agent. A simultaneous, matched-pairs approach was used for region of interest analysis of the entire contrast-enhancing lesion (SI-e), the centre (SI-c), the border of the lesion (SI-b) and the adjacent non-contrast-enhancing tissue (SI-p). SIs of brain metastases and radiation injuries after SRS were compared using a two-level, linear, mixed-effects regression model. In total, 41 lesions were analysed: 16 metastases and 25 radiation injuries. The SI time course of SI-e, SI-c and SI-b proved to be significantly different for both entities (P < 0.001) from TP2 to TP3. The SI of 39/41 lesions increased from TP1 to TP2 for the three parameters. Radiation injuries showed a further signal increase at least for SI-c from TP2 to TP3, whereas for all the three parameters SI decreased in all metastases. Brain metastases and radiation injuries after SRS have a characteristic and statistically significantly different SI time course on sequential gadolinium enhancement MRI when late MR studies are included. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  20. Features of magnetic resonance imaging brain in eclampsia: clinicoradiologic correlation

    Directory of Open Access Journals (Sweden)

    Mubarak F

    2012-08-01

    Full Text Available Fatima Mubarak, Muhammad Idris, Quratulain HadiDepartment of Radiology, Aga Khan University Hospital, Karachi, PakistanObjective: Eclampsia is a gestational hypertensive condition that typically occurs after 20 weeks of pregnancy and is characterized by hypertension, peripheral edema, proteinuria, and seizures. Magnetic resonance imaging (MRI plays a vital role in the diagnosis and management of these patients, so it is essential to describe features of the brain MRI in these cases.Methods: MRI was performed on eleven consecutive patients with eclampsia. All patients underwent follow-up neurologic examinations until all symptoms resolved. Nine of those eleven patients underwent follow-up MRI. The clinical signs and symptoms were correlated with findings on initial and follow-up MRI.Results: MRI typically demonstrated bilateral hyperintense lesions on T2-weighted images and hypointense lesions on T1-weighted images without diffusion restriction. MRI abnormalities are most commonly located in the distribution of the posterior cerebral circulation mainly in occipital and parietal lobes, and are associated with visual disturbances and dizziness. Almost all lesions seen at MRI in patients with eclampsia were reversible in our series of patients.Conclusion: Involvement of the parietal and occipital lobes is common in patients with eclampsia, and the signal abnormalities on MRI are reversible if recognized and treated early.Keywords: pregnancy, seizures, hypertension, brain, MRI findings, reversible

  1. Contrast-enhanced ultrasound imaging for the detection of focused ultrasound-induced blood-brain barrier opening.

    Science.gov (United States)

    Fan, Ching-Hsiang; Lin, Wun-Hao; Ting, Chien-Yu; Chai, Wen-Yen; Yen, Tzu-Chen; Liu, Hao-Li; Yeh, Chih-Kuang

    2014-01-01

    The blood-brain barrier (BBB) can be transiently and locally opened by focused ultrasound (FUS) in the presence of microbubbles (MBs). Various imaging modalities and contrast agents have been used to monitor this process. Unfortunately, direct ultrasound imaging of BBB opening with MBs as contrast agent is not feasible, due to the inability of MBs to penetrate brain parenchyma. However, FUS-induced BBB opening is accompanied by changes in blood flow and perfusion, suggesting the possibility of perfusion-based ultrasound imaging. Here we evaluated the use of MB destruction-replenishment, which was originally developed for analysis of ultrasound perfusion kinetics, for verifying and quantifying FUS-induced BBB opening. MBs were intravenously injected and the BBB was disrupted by 2 MHz FUS with burst-tone exposure at 0.5-0.7 MPa. A perfusion kinetic map was estimated by MB destruction-replenishment time-intensity curve analysis. Our results showed that the scale and distribution of FUS-induced BBB opening could be determined at high resolution by ultrasound perfusion kinetic analysis. The accuracy and sensitivity of this approach was validated by dynamic contrast-enhanced MRI. Our successful demonstration of ultrasound imaging to monitor FUS-induced BBB opening provides a new approach to assess FUS-dependent brain drug delivery, with the benefit of high temporal resolution and convenient integration with the FUS device.

  2. Different impressions of other agents obtained through social interaction uniquely modulate dorsal and ventral pathway activities in the social human brain.

    Science.gov (United States)

    Takahashi, Hideyuki; Terada, Kazunori; Morita, Tomoyo; Suzuki, Shinsuke; Haji, Tomoki; Kozima, Hideki; Yoshikawa, Masahiro; Matsumoto, Yoshio; Omori, Takashi; Asada, Minoru; Naito, Eiichi

    2014-09-01

    Internal (neuronal) representations in the brain are modified by our experiences, and this phenomenon is not unique to sensory and motor systems. Here, we show that different impressions obtained through social interaction with a variety of agents uniquely modulate activity of dorsal and ventral pathways of the brain network that mediates human social behavior. We scanned brain activity with functional magnetic resonance imaging (fMRI) in 16 healthy volunteers when they performed a simple matching-pennies game with a human, human-like android, mechanical robot, interactive robot, and a computer. Before playing this game in the scanner, participants experienced social interactions with each opponent separately and scored their initial impressions using two questionnaires. We found that the participants perceived opponents in two mental dimensions: one represented "mind-holderness" in which participants attributed anthropomorphic impressions to some of the opponents that had mental functions, while the other dimension represented "mind-readerness" in which participants characterized opponents as intelligent. Interestingly, this "mind-readerness" dimension correlated to participants frequently changing their game tactic to prevent opponents from envisioning their strategy, and this was corroborated by increased entropy during the game. We also found that the two factors separately modulated activity in distinct social brain regions. Specifically, mind-holderness modulated activity in the dorsal aspect of the temporoparietal junction (TPJ) and medial prefrontal and posterior paracingulate cortices, while mind-readerness modulated activity in the ventral aspect of TPJ and the temporal pole. These results clearly demonstrate that activity in social brain networks is modulated through pre-scanning experiences of social interaction with a variety of agents. Furthermore, our findings elucidated the existence of two distinct functional networks in the social human brain

  3. Visualizing the blind brain: brain imaging of visual field defects from early recovery to rehabilitation techniques

    Directory of Open Access Journals (Sweden)

    Marika eUrbanski

    2014-09-01

    Full Text Available Visual field defects (VFDs are one of the most common consequences observed after brain injury, especially after a stroke in the posterior cerebral artery territory. Less frequently, tumours, traumatic brain injury, brain surgery or demyelination can also determine various visual disabilities, from a decrease in visual acuity to cerebral blindness. VFD is a factor of bad functional prognosis as it compromises many daily life activities (e.g., obstacle avoidance, driving, and reading and therefore the patient’s quality of life. Spontaneous recovery seems to be limited and restricted to the first six months, with the best chance of improvement at one month. The possible mechanisms at work could be partly due to cortical reorganization in the visual areas (plasticity and/or partly to the use of intact alternative visual routes, first identified in animal studies and possibly underlying the phenomenon of blindsight. Despite processes of early recovery, which is rarely complete, and learning of compensatory strategies, the patient’s autonomy may still be compromised at more chronic stages. Therefore, various rehabilitation therapies based on neuroanatomical knowledge have been developed to improve VFDs. These use eye-movement training techniques (e.g., visual search, saccadic eye movements, reading training, visual field restitution (the Vision Restoration Therapy, VRT, or perceptual learning. In this review, we will focus on studies of human adults with acquired VFDs, which have used different imaging techniques (Positron Emission Tomography: PET, Diffusion Tensor Imaging: DTI, functional Magnetic Resonance Imaging: fMRI, MagnetoEncephalography: MEG or neurostimulation techniques (Transcranial Magnetic Stimulation: TMS; transcranial Direct Current Stimulation, tDCS to show brain activations in the course of spontaneous recovery or after specific rehabilitation techniques.

  4. Brain tumours at 7T MRI compared to 3T - contrast effect after half and full standard contrast agent dose: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Noebauer-Huhmann, Iris-Melanie; Weber, M. [Medical University of Vienna, High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Medical University of Vienna, Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Szomolanyi, P.; Juras, V. [Medical University of Vienna, High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Slovak Academy of Sciences, Department of Imaging Methods, Institute of Measurement Science, Bratislava (Slovakia); Kronnerwetter, C. [Medical University of Vienna, High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Widhalm, G. [Medical University of Vienna, Department of Neurosurgery, Vienna (Austria); Nemec, S.; Prayer, D. [Medical University of Vienna, Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Ladd, M.E. [University Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, Heidelberg (Germany); Trattnig, S. [Medical University of Vienna, High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Austrian Cluster for Tissue Regeneration, Vienna (Austria)

    2015-01-15

    To compare the contrast agent effect of a full dose and half the dose of gadobenate dimeglumine in brain tumours at 7 Tesla (7T) MR versus 3 Tesla (3T). Ten patients with primary brain tumours or metastases were examined. Signal intensities were assessed in the lesion and normal brain. Tumour-to-brain contrast and lesion enhancement were calculated. Additionally, two independent readers subjectively graded the image quality and artefacts. The enhanced mean tumour-to-brain contrast and lesion enhancement were significantly higher at 7T than at 3T for both half the dose (91.8 ± 45.8 vs. 43.9 ± 25.3 [p = 0.010], 128.1 ± 53.7 vs. 75.5 ± 32.4 [p = 0.004]) and the full dose (129.2 ± 50.9 vs. 66.6 ± 33.1 [p = 0.002], 165.4 ± 54.2 vs. 102.6 ± 45.4 [p = 0.004]). Differences between dosages at each field strength were also significant. Lesion enhancement was higher with half the dose at 7T than with the full dose at 3T (p =.037), while the tumour-to-brain contrast was not significantly different. Subjectively, contrast enhancement, visibility, and lesion delineation were better at 7T and with the full dose. All parameters were rated as good, at the least. Half the routine contrast agent dose at 7T provided higher lesion enhancement than the full dose at 3T which indicates the possibility of dose reduction at 7T. (orig.)

  5. Fast high resolution whole brain T2* weighted imaging using echo planar imaging at 7T.

    Science.gov (United States)

    Zwanenburg, Jaco J M; Versluis, Maarten J; Luijten, Peter R; Petridou, Natalia

    2011-06-15

    Magnetic susceptibility based (T(2)* weighted) contrast in MRI at high magnetic field strength is of great value in research on brain structure and cortical architecture, but its use is hampered by the low signal-to-noise ratio (SNR) efficiency of the conventional spoiled gradient echo sequence (GRE) leading to long scan times even for a limited number of slices. In this work, we show that high resolution (0.5mm isotropic) T(2)* weighted images of the whole brain can be obtained in 6min by utilizing the high SNR efficiency of echo-planar imaging (EPI). A volumetric (3D) EPI protocol is presented and compared to conventional 3D GRE images acquired with the same resolution, amount of T(2)* weighting, and imaging duration. Spatial coverage in 3D EPI was increased by a factor of 4.5 compared to 3D GRE, while also the SNR was increased by a factor of 2. Image contrast for both magnitude and phase between gray and white matter was similar for both sequences, with enhanced conspicuity of anatomic details in the 3D EPI images due to the increased SNR. Even at 7T, image blurring and distortion is limited if the EPI train length remains short (not longer than the T(2)* of the imaged tissue). 3D EPI provides steps (speed, whole brain coverage, and high isotropic resolution) that are necessary to utilize the benefits of high field MRI in research that employs T(2)* weighted imaging. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Combined blood pool and extracellular contrast agents for pediatric and young adult cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Joyce T. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Robinson, Joshua D. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Deng, Jie [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Rigsby, Cynthia K. [Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

    2016-12-15

    A comprehensive cardiac magnetic resonance (cardiac MR) study including both late gadolinium enhancement (LGE) and MR angiography may be indicated for patients with a history of acquired or congenital heart disease. To study the novel use of an extracellular agent for assessment of LGE combined with a blood pool contrast agent for detailed MR angiography evaluation to yield a comprehensive cardiac MR study in these patients. We reviewed clinical cardiac MR studies utilizing extracellular and blood pool contrast agents and noted demographics, clinical data and adverse events. We rated LGE image quality and MR angiography image quality for each vascular segment and calculated inter-rater variability. We also quantified contrast-to-noise ratio (CNR). Thirty-three patients (mean age 13.9 ± 3 years) received an extracellular contrast agent (10 gadobenate dimeglumine, 23 gadopentetate dimeglumine) and blood pool contrast agent (33 gadofosveset trisodium). No adverse events were reported. MRI indications included Kawasaki disease (8), cardiomyopathy and coronary anatomy (15), repaired congenital heart disease (8), and other (2). Mean LGE quality was 2.6 ± 0.6 with 97% diagnostic imaging. LGE quality did not vary by type of contrast agent given (P = 0.07). Mean MR angiography quality score was 4.7 ± 0.6, with high inter-rater agreement (k = 0.6-0.8, P < 0.002). MR angiography quality did not vary by type of contrast agent used (P = 0.6). Cardiac MR studies utilizing both extracellular and blood pool contrast agents are feasible and safe and provide excellent-quality LGE and MR angiography images. The use of two contrast agents allows for a comprehensive assessment of both myocardial viability and vascular anatomy during the same exam. (orig.)

  7. Traumatic Intracranial Hemorrhage Correlates with Preinjury Brain Atrophy, but Not with Antithrombotic Agent Use: A Retrospective Study

    OpenAIRE

    Dunham, C. Michael; Hoffman, David A.; Huang, Gregory S.; Omert, Laurel A.; Gemmel, David J.; Merrell, Renee

    2014-01-01

    Background The impact of antithrombotic agents (warfarin, clopidogrel, ASA) on traumatic brain injury outcomes is highly controversial. Although cerebral atrophy is speculated as a risk for acute intracranial hemorrhage, there is no objective literature evidence. Materials and Methods This is a retrospective, consecutive investigation of patients with signs of external head trauma and age ≥60 years. Outcomes were correlated with antithrombotic-agent status, coagulation test results, admission...

  8. Development of Magnetic Resonance Imaging Biomarkers for Traumatic Brain Injury

    Science.gov (United States)

    2013-07-01

    of imaging may provide a means for monitor- ing longitudinal changes in iron content in dementia, multiple sclerosis , traumatic brain injury, and...criteria: Patients aged 18 or older with an initial Glasgow Coma Scale (GCS) score of 3 13-15 in ED with any period of loss of consciousness less than 30...n=18), 61% 8 were men and 39% women, and the average patient age was 34.83±14.30 years. There 9 was no age difference between patient and controls

  9. Brain tumor imaging of rat fresh tissue using terahertz spectroscopy

    Science.gov (United States)

    Yamaguchi, Sayuri; Fukushi, Yasuko; Kubota, Oichi; Itsuji, Takeaki; Ouchi, Toshihiko; Yamamoto, Seiji

    2016-07-01

    Tumor imaging by terahertz spectroscopy of fresh tissue without dye is demonstrated using samples from a rat glioma model. The complex refractive index spectrum obtained by a reflection terahertz time-domain spectroscopy system can discriminate between normal and tumor tissues. Both the refractive index and absorption coefficient of tumor tissues are higher than those of normal tissues and can be attributed to the higher cell density and water content of the tumor region. The results of this study indicate that terahertz technology is useful for detecting brain tumor tissue.

  10. A dual function theranostic agent for near-infrared photoacoustic imaging and photothermal therapy

    Science.gov (United States)

    Upputuri, Paul Kumar; Huang, Shuo; Wang, Mingfeng; Pramanik, Manojit

    2016-03-01

    Theranostic, defined as combining diagnostic and therapeutic agents, has attracted more attention in biomedical application. It is essential to monitor diseased tissue before treatment. Photothermal therapy (PTT) is a promising treatment of cancer tissue due to minimal invasion, unharmful to normal tissue and high efficiency. Photoacoustic tomography (PAT) is a hybrid nonionizing biomedical imaging modality that combines rich optical contrast and high ultrasonic resolution in a single imaging modality. The near infra-red (NIR) wavelengths, usually used in PAT, can provide deep penetration at the expense of reduced contrast, as the blood absorption drops in the NIR range. Exogenous contrast agents with strong absorption in the NIR wavelength range can enhance the photoacoustic imaging contrast as well as imaging depth. Most theranostic agents incorporating PAT and PTT are inorganic nanomaterials that suffer from poor biocompatibility and biodegradability. Herein, we present an benzo[1,2-c;4,5-c'] bis[1,2,5] thiadiazole (BBT), based theranostic agent which not only acts as photoacoustic contrast agent but also a photothermal therapy agent. Experiments were performed on animal blood and organic nanoparticles embedded in a chicken breast tissue using PAT imaging system at ~803 nm wavelengths. Almost ten time contrast enhancement was observed from the nanoparticle in suspension. More than 6.5 time PA signal enhancement was observed in tissue at 3 cm depth. HeLa cell lines was used to test photothermal effect showing 90% cells were killed after 10 min laser irradiation. Our results indicate that the BBT - based naoparticles are promising theranostic agents for PAT imaging and cancer treatment by photothermal therapy.

  11. Parkia biglobosa Improves Mitochondrial Functioning and Protects against Neurotoxic Agents in Rat Brain Hippocampal Slices

    Directory of Open Access Journals (Sweden)

    Kayode Komolafe

    2014-01-01

    Full Text Available Objective. Methanolic leaf extracts of Parkia biglobosa, PBE, and one of its major polyphenolic constituents, catechin, were investigated for their protective effects against neurotoxicity induced by different agents on rat brain hippocampal slices and isolated mitochondria. Methods. Hippocampal slices were preincubated with PBE (25, 50, 100, or 200 µg/mL or catechin (1, 5, or 10 µg/mL for 30 min followed by further incubation with 300 µM H2O2, 300 µM SNP, or 200 µM PbCl2 for 1 h. Effects of PBE and catechin on SNP- or CaCl2-induced brain mitochondrial ROS formation and mitochondrial membrane potential (ΔΨm were also determined. Results. PBE and catechin decreased basal ROS generation in slices and blunted the prooxidant effects of neurotoxicants on membrane lipid peroxidation and nonprotein thiol contents. PBE rescued hippocampal cellular viability from SNP damage and caused a significant boost in hippocampus Na+, K+-ATPase activity but with no effect on the acetylcholinesterase activity. Both PBE and catechin also mitigated SNP- or CaCl2-dependent mitochondrial ROS generation. Measurement by safranine fluorescence however showed that the mild depolarization of the ΔΨm by PBE was independent of catechin. Conclusion. The results suggest that the neuroprotective effect of PBE is dependent on its constituent antioxidants and mild mitochondrial depolarization propensity.

  12. Anatomical Brain Magnetic Resonance Imaging of Typically Developing Children and Adolescents

    Science.gov (United States)

    Giedd, Jay N.; Lalonde, Francois M.; Celano, Mark J.; White, Samantha L.; Wallace, Gregory L.; Lee, Nancy R.; Lenroot, Rhoshel K.

    2009-01-01

    Methodological issues relevant to magnetic resonance imaging studies of brain anatomy are discussed along with the findings on the neuroanatomic changes during childhood and adolescence. The development of the brain is also discussed.

  13. Imaging of Brain Connectivity in Dementia: Clinical Implications for Diagnosis of its Underlying Diseases

    NARCIS (Netherlands)

    R. Meijboom (Rozanna)

    2017-01-01

    markdownabstractIn this thesis we investigated the use of advanced magnetic resonance imaging (MRI) techniques in identifying subtle brain abnormalities, associating brain abnormalities with disease symptomatology, and improving early (differential) diagnosis in several diseases underlying dementia.

  14. Emerging Techniques in Brain Tumor Imaging: What Radiologists Need to Know

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minjae; Kim, Ho Sung [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505 (Korea, Republic of)

    2016-11-01

    Among the currently available brain tumor imaging, advanced MR imaging techniques, such as diffusion-weighted MR imaging and perfusion MR imaging, have been used for solving diagnostic challenges associated with conventional imaging and for monitoring the brain tumor treatment response. Further development of advanced MR imaging techniques and postprocessing methods may contribute to predicting the treatment response to a specific therapeutic regimen, particularly using multi-modality and multiparametric imaging. Over the next few years, new imaging techniques, such as amide proton transfer imaging, will be studied regarding their potential use in quantitative brain tumor imaging. In this review, the pathophysiologic considerations and clinical validations of these promising techniques are discussed in the context of brain tumor characterization and treatment response.

  15. Emerging techniques in brain tumor imaging: What radiologists need to know

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Jae; Kim, Ho Sung [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2016-09-15

    Among the currently available brain tumor imaging, advanced MR imaging techniques, such as diffusion-weighted MR imaging and perfusion MR imaging, have been used for solving diagnostic challenges associated with conventional imaging and for monitoring the brain tumor treatment response. Further development of advanced MR imaging techniques and postprocessing methods may contribute to predicting the treatment response to a specific therapeutic regimen, particularly using multi-modality and multiparametric imaging. Over the next few years, new imaging techniques, such as amide proton transfer imaging, will be studied regarding their potential use in quantitative brain tumor imaging. In this review, the pathophysiologic considerations and clinical validations of these promising techniques are discussed in the context of brain tumor characterization and treatment response.

  16. Microscopy and chemical imaging of Behcet brain tissue

    Science.gov (United States)

    Aranyosiova, Monika; Michalka, Miroslav; Kopani, Martin; Rychly, Boris; Jakubovsky, Jan; Velic, Dusan

    2008-12-01

    Chemical composition and distribution of molecules and elements in a human brain tissue of Behcet diseased patient are of interest. Behcet disease is a multi-system disorder of which pathogenesis and chemical causality are still uncertain. Time-of-flight secondary ion mass spectrometry is used along with scanning electron microscopy and energy dispersive X-ray analysis providing complex composition in Behcet disease and control tissues. Determined organic compounds are represented by fragments of carbohydrates, phospholipids, amino acids, and peptides. The distributions of inorganic species are well represented by heavy trace elements and by oxides in positive and negative polarities of time-of-flight secondary ion mass spectrometry, respectively. Organic and inorganic compounds are qualitatively determined in both samples, Behcet and control, providing complementary chemical images. The complementary chemical images interestingly change with the quantitative regression of organic compounds distribution, characteristic for the healthy control, towards inorganic compounds distribution, characteristic for Behcet tissue.

  17. Serotonin transporter and dopamine transporter imaging in the canine brain

    Energy Technology Data Exchange (ETDEWEB)

    Peremans, Kathelijne [Department of Medical Imaging, Faculty of Veterinary Sciences, Ghent University, B-9000 Ghent (Belgium); Goethals, Ingeborg [Division of Nuclear Medicine, University Hospital Ghent, B-9000 Ghent (Belgium); De Vos, Filip [Laboratory of Radiopharmacy, Pharmaceutical Sciences, Ghent University, B-9000 Ghent (Belgium); Dobbeleir, A. [Department of Medical Imaging, Faculty of Veterinary Sciences, Ghent University, B-9000 Ghent (Belgium); Ham, Hamphrey [Division of Nuclear Medicine, University Hospital Ghent, B-9000 Ghent (Belgium); Van Bree, Henri [Department of Medical Imaging, Faculty of Veterinary Sciences, Ghent University, B-9000 Ghent (Belgium); Heeringen, Cees van [Department of Psychiatry and Medical Psychology, Faculty of Medical and Health Sciences, Ghent University, B-9000, Ghent (Belgium); Audenaert, Kurt [Division of Nuclear Medicine, University Hospital Ghent, B-9000 Ghent (Belgium) and Department of Psychiatry and Medical Psychology, Faculty of Medical and Health Sciences, Ghent University, B-9000, Ghent (Belgium)]. E-mail: kurt.audenaert@ugent.be

    2006-10-15

    The serotonergic and dopaminergic systems are involved in a wide range of emotional and behavioral aspects of animals and humans and are involved in many neuropsychiatric disorders. Selective serotonin (5-HT) reuptake inhibitors (SSRIs) are designed to block the 5-HT transporter (SERT), thereby increasing the available 5-HT in the brain. Functional imaging with specific SERT and dopamine transporter (DAT) ligands contributes to the study of the SSRI-transporter interaction. First, we evaluated the feasibility of a canine model in the study of the SERT and DAT with the radioligands [{sup 123}I]-{beta}-CIT and [{sup 123}I]-FP-CIT as well as single-photon emission computed tomography imaging. Second, we studied the effect of SSRIs (sertraline, citalopram and escitalopram) on the SERT and DAT in two dogs. The position of the canine model in the study of the SERT and DAT is discussed and compared with other animal models.

  18. Graphene Meets Microbubbles: A Superior Contrast Agent for Photoacoustic Imaging.

    Science.gov (United States)

    Toumia, Yosra; Domenici, Fabio; Orlanducci, Silvia; Mura, Francesco; Grishenkov, Dmitry; Trochet, Philippe; Lacerenza, Savino; Bordi, Federico; Paradossi, Gaio

    2016-06-29

    Coupling graphene with a soft polymer surface offers the possibility to build hybrid constructs with new electrical, optical, and mechanical properties. However, the low reactivity of graphene is a hurdle in the synthesis of such systems which is often bypassed by oxidizing its carbon planar structure. However, the defects introduced with this process jeopardize the properties of graphene. In this paper we present a different approach, applicable to many different polymer surfaces, which uses surfactant assisted ultrasonication to exfoliate, and simultaneously suspend, graphene in water in its intact form. Tethering pristine graphene sheets to the surfaces is accomplished by using suitable reactive functional groups of the surfactant scaffold. We focused on applying this approach to the fabrication of a hybrid system, made of pristine graphene tethered to poly(vinyl alcohol) based microbubbles (PVA MBs), designed for enhancing photoacoustic signals. Photoacoustic imaging (PAI) is a powerful preclinical diagnostic tool which provides real time images at a resolution of 40 μm. The leap toward clinical imaging has so far been hindered by the limited tissues penetration of near-infrared (NIR) pulsed laser radiation. Many academic and industrial research laboratories have met this challenge by designing devices, each with pros and cons, to enhance the photoacoustic (PA) signal. The major advantages of the hybrid graphene/PVA MBs construct, however, are (i) the preservation of graphene properties, (ii) biocompatibility, a consequence of the robust anchoring of pristine graphene to the bioinert surface of the PVA bubble, and (iii) a very good enhancement in a NIR spectral region of the PA signal, which does not overlap with the signals of PA active endogenous molecules such as hemoglobin.

  19. Dynamic manipulation of magnetic contrast agents in photoacoustic imaging

    Science.gov (United States)

    Jia, Congxian; Xia, Jinjun; Pelivanov, Ivan M.; Seo, Chi Hyung; Hu, Xiaoge; Jin, Yongdong; Gao, Xiaohu; O'Donnell, Matthew

    2011-03-01

    Magnetic nanoparticles (MNPs) have been used extensively ex vivo for cellular and molecular separations. We recently showed that a coupled nanoparticle combining a superparamagnetic core with a thin, isolated gold shell providing strong absorption in the near infrared can be used for magnetomotive photoacoustic imaging (mmPA), a new technique in which magnetic manipulation of the particle during PA imaging greatly enhances molecular contrast specificity. This particle can also be biologically targeted for in vivo applications, where mmPA imaging provides a spatially localized readout of magnetic manipulations. As an initial test of potential in vivo molecular assays and integrated molecular therapeutics using magnetic manipulation of nanoparticles, we present experiments demonstrating PA readout of trapped magnetic particles in a flow field. An aqueous solution containing a concentration of 0.05-mg/ml 10-μM superparamagnetic iron oxide particles flowed in a 1.65-mm diameter Zeus PTFE (Teflon) sublite wall tubing at three velocities of 0.8, 1.5 and 3.0-mm/s. Opposed permanent magnets separated by 40-mm were positioned on both sides of the tube. As expected, the targeted objects can be magnetically captured and accumulated locally. By translating the magnets, a dynamic magnetic field (0.1-0.3-T) was alternately generated on the side of the tube closest to one of the magnets and created a synchronous PA motion from accumulated targeted objects. This synchronized motion can be used to differentiate the stationary background or other PA sources moving asynchronously with magnetic manipulations (e.g., moving blood) from targeted cells moving synchronously with the magnetic field. This technology can potentially provide sensitive molecular assays of cellular targets travelling in the vasculature (e.g., metastatic tumor cells).

  20. Clearance properties of nano-sized particles and molecules as imaging agents: considerations and caveats.

    Science.gov (United States)

    Longmire, Michelle; Choyke, Peter L; Kobayashi, Hisataka

    2008-10-01

    Nanoparticles possess enormous potential as diagnostic imaging agents and hold promise for the development of multimodality agents with both imaging and therapeutic capabilities. Yet, some of the most promising nanoparticles demonstrate prolonged tissue retention and contain heavy metals. This presents serious concerns for toxicity. The creation of nanoparticles with optimal clearance characteristics will minimize toxicity risks by reducing the duration of exposure to these agents. Given that many nanoparticles possess easily modifiable surface and interior chemistry, if nanoparticle characteristics associated with optimal clearance from the body were well established, it would be feasible to design and create agents with more favorable clearance properties. This article presents a thorough discussion of the physiologic aspects of nanoparticle clearance, focusing on renal mechanisms, and provides an overview of current research investigating clearance of specific types of nanoparticles and nano-sized macromolecules, including dendrimers, quantum dots, liposomes and carbon, gold and silica-based nanoparticles.

  1. Synthesis and characterization of ethosomal contrast agents containing iodine for computed tomography (CT) imaging applications.

    Science.gov (United States)

    Shin, Hanjin; Cho, Young-Min; Lee, Kangtaek; Lee, Chang-Ha; Choi, Byoung Wook; Kim, Bumsang

    2014-06-01

    As a first step in the development of novel liver-specific contrast agents using ethosomes for computed tomography (CT) imaging applications, we entrapped iodine within ethosomes, which are phospholipid vesicular carriers containing relatively high alcohol concentrations, synthesized using several types of alcohol, such as methanol, ethanol, and propanol. The iodine containing ethosomes that were prepared using methanol showed the smallest vesicle size (392 nm) and the highest CT density (1107 HU). The incorporation of cholesterol into the ethosomal contrast agents improved the stability of the ethosomes but made the vesicle size large. The ethosomal contrast agents were taken up well by macrophage cells and showed no cellular toxicity. The results demonstrated that ethosomes containing iodine, as prepared in this study, have potential as contrast agents for applications in CT imaging.

  2. Prospective analysis on brain magnetic resonance imaging in children.

    Science.gov (United States)

    Biebl, Ariane; Frechinger, Bettina; Fellner, Christine Maria; Ehrenmüller, Margit; Povysil, Brigitte; Fellner, Franz; Schmitt, Klaus; Furthner, Dieter

    2015-05-01

    Previous studies have addressed the prevalence of incidental findings in adult populations. There are few studies following paediatric patients, most of data were retrieved retrospectively. We conducted a prospective study to determine the prevalence of incidental, pathologic and normal findings in a symptomatic paediatric population. The subjects of this prospective single centre study are 436 children aged 0-18 years with clinical symptoms and subsequent first brain MRI. Normal, incidental as well as pathologic MRI findings are documented in association with age, gender, neurological examination and previous investigations (CCT, EEG). Secondary outcome parameters are defined as MRI results and their implications. Two board-certified radiologists prospectively analysed MR images without knowing the result from each other. The 436 patients with brain MRI were categorized into three groups as follows: 155 (35.5%) patients had normal findings, 163 (37.4%) had incidental findings and 118 (27.1%) had pathological findings in brain MRI. When adding patients with pathologic and incidental findings we report even more (47.9%). We analysed the correlation between neurologic examination and MRI result and it was significant (p-value 0.0008). The p-value for concordance of both radiology reports was MRI in symptomatic children. Incidental findings are common in paediatric patients but we report the highest prevalence. Our data may help guiding management decision in a consistent and clinically appropriate manner. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  3. Early Diagnosis of Orthopedic Implant Failure Using Macromolecular Imaging Agents

    Science.gov (United States)

    Ren, Ke; Dusad, Anand; Zhang, Yijia; Purdue, P. Edward; Fehringer, Edward V.; Garvin, Kevin L.; Goldring, Steven R.; Wang, Dong

    2014-01-01

    Purpose To develop and evaluate diagnostic tools for early detection of wear particle-induced orthopaedic implant loosening. Methods N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer was tagged with an near infrared dye and used to detect the inflammation induced by polymethylmethacrylate (PMMA) particles in a murine peri-implant osteolysis model. It was established by inserting implant into distal femur and with routine PMMA particles challenging. The osteolysis was evaluated by micro-CT and histological analysis at different time points. Results Significant peri-implant osteolysis was found three-month post PMMA particle challenge by micro-CT and histological analysis. At one-month time point, when there was no significant peri-implant bone loss, HPMA copolymer-near infrared dye conjugate was found to specifically target to the femur with PMMA particles deposition, but not the contralateral control femur with PBS infusion. Conclusion The results from this study demonstrated the feasibility of utilizing the macromolecular diagnostic agent to report particle-induced peri-implant inflammation prior to the development of detectable osteolysis. Recognition of this early pathological event would provide the window of opportunity for prevention of peri-implant osteolysis and subsequent orthopaedic implant failure. PMID:24590878

  4. Exogenous contrast agents for thermoacoustic imaging: an investigation into the underlying sources of contrast.

    OpenAIRE

    Ogunlade, O.; Beard, P

    2015-01-01

    Thermoacoustic imaging at microwave excitation frequencies is limited by the low differential contrast exhibited by high water content tissues. To overcome this, exogenous thermoacoustic contrast agents based on gadolinium compounds, iron oxide, and single wall carbon nanotubes have previously been suggested and investigated. However, these previous studies did not fully characterize the electric, magnetic, and thermodynamic properties of these agents thus precluding identification of the und...

  5. What is feasible with imaging human brain function and connectivity using functional magnetic resonance imaging.

    Science.gov (United States)

    Ugurbil, Kamil

    2016-10-05

    When we consider all of the methods we employ to detect brain function, from electrophysiology to optical techniques to functional magnetic resonance imaging (fMRI), we do not really have a 'golden technique' that meets all of the needs for studying the brain. We have methods, each of which has significant limitations but provide often complimentary information. Clearly, there are many questions that need to be answered about fMRI, which unlike other methods, allows us to study the human brain. However, there are also extraordinary accomplishments or demonstration of the feasibility of reaching new and previously unexpected scales of function in the human brain. This article reviews some of the work we have pursued, often with extensive collaborations with other co-workers, towards understanding the underlying mechanisms of the methodology, defining its limitations, and developing solutions to advance it. No doubt, our knowledge of human brain function has vastly expanded since the introduction of fMRI. However, methods and instrumentation in this dynamic field have evolved to a state that discoveries about the human brain based on fMRI principles, together with information garnered at a much finer spatial and temporal scale through other methods, are poised to significantly accelerate in the next decade.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. © 2016 The Author(s).

  6. What is feasible with imaging human brain function and connectivity using functional magnetic resonance imaging

    Science.gov (United States)

    2016-01-01

    When we consider all of the methods we employ to detect brain function, from electrophysiology to optical techniques to functional magnetic resonance imaging (fMRI), we do not really have a ‘golden technique’ that meets all of the needs for studying the brain. We have methods, each of which has significant limitations but provide often complimentary information. Clearly, there are many questions that need to be answered about fMRI, which unlike other methods, allows us to study the human brain. However, there are also extraordinary accomplishments or demonstration of the feasibility of reaching new and previously unexpected scales of function in the human brain. This article reviews some of the work we have pursued, often with extensive collaborations with other co-workers, towards understanding the underlying mechanisms of the methodology, defining its limitations, and developing solutions to advance it. No doubt, our knowledge of human brain function has vastly expanded since the introduction of fMRI. However, methods and instrumentation in this dynamic field have evolved to a state that discoveries about the human brain based on fMRI principles, together with information garnered at a much finer spatial and temporal scale through other methods, are poised to significantly accelerate in the next decade. This article is part of the themed issue ‘Interpreting BOLD: a dialogue between cognitive and cellular neuroscience’. PMID:27574313

  7. Optimizing brain tumor resection. Midfield interventional MR imaging.

    Science.gov (United States)

    Alexander, E

    2001-11-01

    The development of the intraoperative MR imager represents an important example of creative vision and interdisciplinary teamwork. The result is a remarkable tool for neurosurgical applications. MRT allows surgical manipulation under direct visualization of the intracranial contents through the eye of the surgeon and through the volumetric images of the MR imaging system. This technology can be applied to cranial and spinal cases, and forseeably can encompass application to the entire gamut of neurosurgical efforts. The author's experience has been that this device is easy and comfortable for the surgeon to use. Image acquisition, giving views in the plane of choice, lasts no more than 2 to 60 seconds (depending on the imaging method), and does not increase the duration of a given procedure substantially. The author believes that the information received through intraoperative MR imaging scanning ultimately will contribute to decreasing the duration of surgery. Future possibilities include combining the intraoperative MR imager with other technologies, such as the endoscope, focused ultrasound, robotics, and the evaluation of brain function intraoperatively. The development of the intraoperative MR imager marks a significant advance in neurosurgery, an advance that will revolutionize intraoperative visualization as fully as the operating microscope. The combination of intraoperative visualization and precise surgical navigation is unparalleled, and its enhancement of surgical applications will be widespread. Considering the remarkable potential of the intraoperative MR imager for neurosurgical applications, optimal magnet design, image quality, and navigational methods are necessary to capitalize on the advantages of this revolutionary tool. The intraoperative MR imaging system that the author's team has developed and used has combined these features, and allows the performance of open surgical procedures without the need of patient or magnet repositioning. By

  8. Diethylenetriaminepentaacetic acid-gadolinium (DTPA-Gd)-conjugated polysuccinimide derivatives as magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Lee, Ha Young; Jee, Hye Won; Seo, Sung Mi; Kwak, Byung Kook; Khang, Gilson; Cho, Sun Hang

    2006-01-01

    Biocompatible polysuccinimide (PSI) derivatives conjugated with diethylenetriaminepentaacetic acid gadolinium (DTPA-Gd) were prepared as magnetic resonance imaging (MRI) contrast agents. In this study, we synthesized PSI derivatives incorporating methoxy-poly(ethylene glycol) (mPEG) as hydrophilic ligand, hexadecylamine as hydrophobic ligand, and DTPA-Gd as contrast agent. PSI was synthesized by the polycondensation polymerization of aspartic acid. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Critical micellization concentrations were determined using fluorescent probes (pyrene). Micelle size and shape were measured by electro-photometer light scattering (ELS) and atomic force microscopy (AFM). The formed micelle size ranged from 100 to 300 nm. The T1-weighted MR images of the phantom prepared with PSI-mPEG-C16-(DTPA-Gd) were obtained in a 3.0 T clinical MR imager, and the conjugates showed a great potential as MRI contrast agents.

  9. Diffusion-weighted imaging in normal fetal brain maturation

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, J.F. [University Children' s Hospital UKBB, Department of Pediatric Radiology, Basel (Switzerland); Confort-Gouny, S.; Le Fur, Y.; Viout, P.; Cozzone, P. [UMR-CNRS 6612, Faculte de Medecine, Universite de la Mediterranee, Centre de Resonance Magnetique Biologique et Medicale, Marseille (France); Bennathan, M.; Chapon, F.; Fogliarini, C.; Girard, N. [Universite de la Mediterranee, Department of Neuroradiology AP-HM Timone, Marseille (France)

    2007-09-15

    Diffusion-weighted imaging (DWI) provides information about tissue maturation not seen on conventional magnetic resonance imaging. The aim of this study is to analyze the evolution over time of the apparent diffusion coefficient (ADC) of normal fetal brain in utero. DWI was performed on 78 fetuses, ranging from 23 to 37 gestational weeks (GW). All children showed at follow-up a normal neurological evaluation. ADC values were obtained in the deep white matter (DWM) of the centrum semiovale, the frontal, parietal, occipital and temporal lobe, in the cerebellar hemisphere, the brainstem, the basal ganglia (BG) and the thalamus. Mean ADC values in supratentorial DWM areas (1.68 {+-} 0.05 mm{sup 2}/s) were higher compared with the cerebellar hemisphere (1.25 {+-} 0.06 mm{sup 2}/s) and lowest in the pons (1.11 {+-} 0.05 mm{sup 2}/s). Thalamus and BG showed intermediate values (1.25 {+-} 0.04 mm{sup 2}/s). Brainstem, cerebellar hemisphere and thalamus showed a linear negative correlation with gestational age. Supratentorial areas revealed an increase in ADC values, followed by a decrease after the 30th GW. This study provides a normative data set that allows insights in the normal fetal brain maturation in utero, which has not yet been observed in previous studies on premature babies. (orig.)

  10. Imaging structural and functional brain networks in temporal lobe epilepsy

    Science.gov (United States)

    Bernhardt, Boris C.; Hong, SeokJun; Bernasconi, Andrea; Bernasconi, Neda

    2013-01-01

    Early imaging studies in temporal lobe epilepsy (TLE) focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing the topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy. PMID:24098281

  11. Postnatal brain development: Structural imaging of dynamic neurodevelopmental processes

    Science.gov (United States)

    Jernigan, Terry L.; Baaré, William F. C.; Stiles, Joan; Madsen, Kathrine Skak

    2013-01-01

    After birth, there is striking biological and functional development of the brain’s fiber tracts as well as remodeling of cortical and subcortical structures. Behavioral development in children involves a complex and dynamic set of genetically guided processes by which neural structures interact constantly with the environment. This is a protracted process, beginning in the third week of gestation and continuing into early adulthood. Reviewed here are studies using structural imaging techniques, with a special focus on diffusion weighted imaging, describing age-related brain maturational changes in children and adolescents, as well as studies that link these changes to behavioral differences. Finally, we discuss evidence for effects on the brain of several factors that may play a role in mediating these brain–behavior associations in children, including genetic variation, behavioral interventions, and hormonal variation associated with puberty. At present longitudinal studies are few, and we do not yet know how variability in individual trajectories of biological development in specific neural systems map onto similar variability in behavioral trajectories. PMID:21489384

  12. Ultrasound imaging for cavitation detection during HIFU ablation in brain

    Science.gov (United States)

    Long, Tao; Amin, Viren; McClure, Scott; Roberts, Ronald; Wu, Liangshou; Heise, Matthew; Ryken, Timothy

    2007-03-01

    High intensity focused ultrasound (abbreviated as HIFU) has its potential in tumor treatment due to its non-invasive benefits. During HIFU exposure, cavitation (generation of gas bubbles) is often observed, which can be an indication of potential lesion created by HIFU power. Due to a large difference in ultrasound acoustic properties between the gas bubble and surrounding tissues, ultrasonic energy is reflected and scattered at the HIFU focus, thus indicating activity around the focal area and often interfering HIFU dosage delivery. A good understanding and control of cavitation phenomenon could potentially enhance the HIFU delivery and treatment outcomes. Quantifying the onset timing and extent of the cavitation could be potentially used for detecting HIFU effects and therapy guidance. In this paper, we study the relationships among HIFU parameters, the characteristics of cavitation quantified from ultrasound imaging, and characteristics of the final tissue lesion created by HIFU. In our study, we used 12 freshly excised pig brains in vitro for observation and analysis of cavitation activities during HIFU exposure with different HIFU parameters. Final lesions were examined by slicing the brain tissues into thin slices and 3D volume was constructed with segmentation of the lesion. HIFU parameters, cavitation activities through image processing and lesion characterization were correlated. We also present our initial understanding of the process of cavitation activities under certain HIFU parameters and control of such activities that could lead to optimal lesion

  13. Intravenous ultrasound contrast agents versus other imaging methods in pediatric patients with neoplastic diseases - a comparison.

    Science.gov (United States)

    Piskunowicz, Maciej; Kosiak, Wojciech; Batko, Tomasz; Adamkiewicz-Drożyńska, Elżbieta; Szarmach, Arkadiusz

    2013-12-01

    The lack of registration of ultrasound contrast agents for use in patients below the age of 18 is a significant limitation of their usage. Despite this, examinations with the use of contrast agents are conducted in numerous centers, mainly as part of the diagnostic process of vesicoureteral reflux. Examinations after an intravenous administration of contrast agents are conducted rarely. The reason for this is not only the lack of registration, but also the lack of studies on their safety profile in paediatric patients or no guidelines concerning the dosage. It seems that imaging with the use of such agents could help solve certain clinical problems when other diagnostic methods fail. The paper presents selected cases of pediatric patients treated in oncological departments, in whom the examination with the use of ultrasound contrast agents had a considerable influence on the diagnostic and therapeutic process.

  14. EPR and DNP Properties of Certain Novel Single Electron Contrast Agents Intended for Oximetric Imaging

    DEFF Research Database (Denmark)

    Ardenkjær-Larsen, J. H.; Laursen, I; Leunbach, I.

    1998-01-01

    Parameters of relevance to oximetry with Overhauser magnetic resonance imaging (OMRI) have been measured for three single electron contrast agents of the triphenylmethyl type. The single electron contrast agents are stable and water soluble. Magnetic resonance properties of the agents have been...... examined with electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), and dynamic nuclear polarization (DNP) at 9.5 mT in water, isotonic saline, plasma, and blood at 23 and 37°C. The relaxivities of the agents are about 0.2–0.4 mM−1s−1and the DNP enhancements extrapolate close...... than 1 μT in water at room temperature. The longitudinal electron spin relaxation rate is calculated from the DNP enhancement curves. The oxygen broadening in water is about 50 μT/mM O2at 37°C. These agents have good properties for oximetry with OMRI....

  15. Residual Deconvolutional Networks for Brain Electron Microscopy Image Segmentation.

    Science.gov (United States)

    Fakhry, Ahmed; Zeng, Tao; Ji, Shuiwang

    2017-02-01

    Accurate reconstruction of anatomical connections between neurons in the brain using electron microscopy (EM) images is considered to be the gold standard for circuit mapping. A key step in obtaining the reconstruction is the ability to automatically segment neurons with a precision close to human-level performance. Despite the recent technical advances in EM image segmentation, most of them rely on hand-crafted features to some extent that are specific to the data, limiting their ability to generalize. Here, we propose a simple yet powerful technique for EM image segmentation that is trained end-to-end and does not rely on prior knowledge of the data. Our proposed residual deconvolutional network consists of two information pathways that capture full-resolution features and contextual information, respectively. We showed that the proposed model is very effective in achieving the conflicting goals in dense output prediction; namely preserving full-resolution predictions and including sufficient contextual information. We applied our method to the ongoing open challenge of 3D neurite segmentation in EM images. Our method achieved one of the top results on this open challenge. We demonstrated the generality of our technique by evaluating it on the 2D neurite segmentation challenge dataset where consistently high performance was obtained. We thus expect our method to generalize well to other dense output prediction problems.

  16. Brain MR imaging finding in patients with central vertigo

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Chun Keun; Kim, Sang Joon; Kim, You Me; Cha, Min Jung; Lee, Young Seok; Kim, Jae Il; Lee, Geun Ho; Rhee, Chung Koo; Park, Hyun Min [Dankook Univ. College of Medicine, Chonan (Korea, Republic of)

    1998-11-01

    To investigate brain lesions and their locations in patients with central vertigo, as seen on MR imaging. We retrospectively reviewed MR images of 85 patients with central type vertigo diagnosed on the basis of clinical symptoms and vestibular function test(VFT), and analyzed lesions fand their locations. Those located along the known central vestibular pathway were included in our study. In 29 of 85 patients(34%), lesions considered to be associated with central vertigo were detected on MR imaging. These included infarction(18 patients), hemorrhage(5), tumor(2), cavernous angioma(1), cerebellopontine angle cyst(1), tuberous sclerosis(1) and olivopontocerebellar atrophy (1);they were located in the parietal lobe(6 patients), the lateral medulla(5), the pons(5), the middle cerebellar peduncle(4), the corona radiata(3), and the cerebellar vermis(3). Thirty-eight cases showed high signal intensity lesions in deep cerebral matter, the basal ganglia, and pons but these were considered to be unrelated to central vertigo. MR imaging could be a useful tool for the evaluation of patients with central vertigo.=20.

  17. Functional brain imaging of episodic memory decline in ageing.

    Science.gov (United States)

    Nyberg, L

    2017-01-01

    The episodic long-term memory system supports remembering of events. It is considered to be the most age-sensitive system, with an average onset of decline around 60 years of age. However, there is marked interindividual variability, such that some individuals show faster than average change and others show no or very little change. This variability may be related to the risk of developing dementia, with elevated risk for individuals with accelerated episodic memory decline. Brain imaging with functional magnetic resonance imaging (MRI) of blood oxygen level-dependent (BOLD) signalling or positron emission tomography (PET) has been used to reveal the brain bases of declining episodic memory in ageing. Several studies have demonstrated a link between age-related episodic memory decline and the hippocampus during active mnemonic processing, which is further supported by studies of hippocampal functional connectivity in the resting state. The hippocampus interacts with anterior and posterior neocortical regions to support episodic memory, and alterations in hippocampus-neocortex connectivity have been shown to contribute to impaired episodic memory. Multimodal MRI studies and more recently hybrid MRI/PET studies allow consideration of various factors that can influence the association between the hippocampal BOLD signal and memory performance. These include neurovascular factors, grey and white matter structural alterations, dopaminergic neurotransmission, amyloid-Β and glucose metabolism. Knowledge about the brain bases of episodic memory decline can guide interventions to strengthen memory in older adults, particularly in those with an elevated risk of developing dementia, with promising results for combinations of cognitive and physical stimulation. © 2016 The Association for the Publication of the Journal of Internal Medicine.

  18. PET imaging reveals brain functional changes in internet gaming disorder.

    Science.gov (United States)

    Tian, Mei; Chen, Qiaozhen; Zhang, Ying; Du, Fenglei; Hou, Haifeng; Chao, Fangfang; Zhang, Hong

    2014-07-01

    Internet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D2 (D2)/Serotonin 2A (5-HT2A) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D2 receptor and glucose metabolism. Twelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and (11)C-N-methylspiperone ((11)C-NMSP) to assess the availability of D2/5-HT2A receptors and with (18)F-fluoro-D-glucose ((18)F-FDG) to assess regional brain glucose metabolism, a marker of brain function. (11)C-NMSP and (18)F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states. In internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D2 receptors was observed in the striatum, and was correlated to years of overuse. A low level of D2 receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex. For the first time, we report the evidence that D2 receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D2/5-HT2A receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects.

  19. PET imaging reveals brain functional changes in internet gaming disorder

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Mei; Zhang, Ying; Du, Fenglei; Hou, Haifeng; Chao, Fangfang; Zhang, Hong [The Second Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou (China); Chen, Qiaozhen [The Second Hospital of Zhejiang University School of Medicine, Department of Nuclear Medicine, Hangzhou, Zhejiang (China); The Second Affiliated Hospital of Zhejiang University School of Medicine, Department of Psychiatry, Hangzhou (China)

    2014-07-15

    Internet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D{sub 2} (D{sub 2})/Serotonin 2A (5-HT{sub 2A}) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D{sub 2} receptor and glucose metabolism. Twelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and {sup 11}C-N-methylspiperone ({sup 11}C-NMSP) to assess the availability of D{sub 2}/5-HT{sub 2A} receptors and with {sup 18}F-fluoro-D-glucose ({sup 18}F-FDG) to assess regional brain glucose metabolism, a marker of brain function. {sup 11}C-NMSP and {sup 18}F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states. In internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D{sub 2} receptors was observed in the striatum, and was correlated to years of overuse. A low level of D{sub 2} receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex. For the first time, we report the evidence that D{sub 2} receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D{sub 2}/5-HT{sub 2A} receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects. (orig.)

  20. A Review of Magnetic Resonance Imaging and Diffusion Tensor Imaging Findings in Mild Traumatic Brain Injury

    Science.gov (United States)

    Shenton, ME; Hamoda, HM; Schneiderman, JS; Bouix, S; Pasternak, O; Rathi, Y; M-A, Vu; Purohit, MP; Helmer, K; Koerte, I; Lin, AP; C-F, Westin; Kikinis, R; Kubicki, M; Stern, RA; Zafonte, R

    2013-01-01

    Mild traumatic brain injury (mTBI), also referred to as concussion, remains a controversial diagnosis because the brain often appears quite normal on conventional computed tomography (CT) and magnetic resonance imaging (MRI) scans. Such conventional tools, however, do not adequately depict brain injury in mTBI because they are not sensitive to detecting diffuse axonal injuries (DAI), also described as traumatic axonal injuries (TAI), the major brain injuries in mTBI. Furthermore, for the 15 to 30% of those diagnosed with mTBI on the basis of cognitive and clinical symptoms, i.e., the “miserable minority,” the cognitive and physical symptoms do not resolve following the first three months post-injury. Instead, they persist, and in some cases lead to long-term disability. The explanation given for these chronic symptoms, i.e., postconcussive syndrome, particularly in cases where there is no discernible radiological evidence for brain injury, has led some to posit a psychogenic origin. Such attributions are made all the easier since both post-traumatic stress disorder (PTSD) and depression are frequently co-morbid with mTBI. The challenge is thus to use neuroimaging tools that are sensitive to DAI/TAI, such as diffusion tensor imaging (DTI), in order to detect brain injuries in mTBI. Of note here, recent advances in neuroimaging techniques, such as DTI, make it possible to characterize better extant brain abnormalities in mTBI. These advances may lead to the development of biomarkers of injury, as well as to staging of reorganization and reversal of white matter changes following injury, and to the ability to track and to characterize changes in brain injury over time. Such tools will likely be used in future research to evaluate treatment efficacy, given their enhanced sensitivity to alterations in the brain. In this article we review the incidence of mTBI and the importance of characterizing this patient population using objective radiological measures. Evidence

  1. Meta-analysis of functional brain imaging in specific phobia.

    Science.gov (United States)

    Ipser, Jonathan C; Singh, Leesha; Stein, Dan J

    2013-07-01

    Although specific phobia is a prevalent anxiety disorder, evidence regarding its underlying functional neuroanatomy is inconsistent. A meta-analysis was undertaken to identify brain regions that were consistently responsive to phobic stimuli, and to characterize changes in brain activation following cognitive behavioral therapy (CBT). We searched the PubMed, SCOPUS and PsycINFO databases to identify positron emission tomography and functional magnetic resonance imaging studies comparing brain activation in specific phobia patients and healthy controls. Two raters independently extracted study data from all the eligible studies, and pooled coordinates from these studies using activation likelihood estimation, a quantitative meta-analytic technique. Resulting statistical parametric maps were compared between patients and healthy controls, in response to phobic versus fear-evoking stimuli, and before and after therapy. Thirteen studies were included, comprising 327 participants. Regions that were consistently activated in response to phobic stimuli included the left insula, amygdala, and globus pallidus. Compared to healthy controls, phobic subjects had increased activation in response to phobic stimuli in the left amygdala/globus pallidus, left insula, right thalamus (pulvinar), and cerebellum. Following exposure-based therapy widespread deactivation was observed in the right frontal cortex, limbic cortex, basal ganglia and cerebellum, with increased activation detected in the thalamus. Exposure to phobia-specific stimuli elicits brain activation that is consistent with current understandings of the neuroanatomy of fear conditioning and extinction. There is evidence that the effects of CBT in specific phobia may be mediated through the same underlying neurocircuitry. © 2013 The Authors. Psychiatry and Clinical Neurosciences © 2013 Japanese Society of Psychiatry and Neurology.

  2. Submicron polycaprolactone particles as a carrier for imaging contrast agent for in vitro applications.

    Science.gov (United States)

    Iqbal, Muhammad; Robin, Sophie; Humbert, Philippe; Viennet, Céline; Agusti, Geraldine; Fessi, Hatem; Elaissari, Abdelhamid

    2015-12-01

    Fluorescent materials have recently attracted considerable attention due to their unique properties and high performance as imaging agent in biomedical fields. Different imaging agents have been encapsulated in order to restrict its delivery to a specific area. In this study, a fluorescent contrast agent was encapsulated for in vitro application by polycaprolactone (PCL) polymer. The encapsulation was performed using modified double emulsion solvent evaporation technique with sonication. Fluorescent nanoparticles (20 nm) were incorporated in the inner aqueous phase of double emulsion. A number of samples were fabricated using different concentrations of fluorescent contrast agent. The contrast agent-containing submicron particle was characterized by a zetasizer for average particle size, SEM and TEM for morphology observations and fluorescence spectrophotometer for encapsulation efficiency. Moreover, contrast agent distribution in the PCL matrix was determined by confocal microscopy. The incorporation of contrast agent in different concentrations did not affect the physicochemical properties of PCL particles and the average size of encapsulated particles was found to be in the submicron range. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Regional distribution of halopemide, a new psychotropic agent, in the rat brain at different time intervals and after chronic administration

    NARCIS (Netherlands)

    Loonen, A.J.M.; Van Wijngaarden, I.; Janssen, P.A.J.; Soudijn, W.

    1979-01-01

    Only a very small amount of halopemide, a new psychotropic agent, structurally related to the butyrophenones, but with a different pharmacological and clinical profile, penetrates into the rat brain. The maximum concentration is reached between 1 and 2 hours after injection. Halopemide is evenly

  4. Simultaneous QSM and metabolic imaging of the brain using SPICE.

    Science.gov (United States)

    Peng, Xi; Lam, Fan; Li, Yudu; Clifford, Bryan; Liang, Zhi-Pei

    2018-01-01

    To map brain metabolites and tissue magnetic susceptibility simultaneously using a single three-dimensional 1 H-MRSI acquisition without water suppression. The proposed technique builds on a subspace imaging method called spectroscopic imaging by exploiting spatiospectral correlation (SPICE), which enables ultrashort echo time (TE)/short pulse repetition time (TR) acquisitions for 1 H-MRSI without water suppression. This data acquisition scheme simultaneously captures both the spectral information of brain metabolites and the phase information of the water signals that is directly related to tissue magnetic susceptibility variations. In extending this scheme for simultaneous QSM and metabolic imaging, we increase k-space coverage by using dual density sparse sampling and ramp sampling to achieve spatial resolution often required by QSM, while maintaining a reasonable signal-to-noise ratio (SNR) for the spatiospectral data used for metabolite mapping. In data processing, we obtain high-quality QSM from the unsuppressed water signals by taking advantage of the larger number of echoes acquired and any available anatomical priors; metabolite spatiospectral distributions are reconstructed using a union-of-subspaces model. In vivo experimental results demonstrate that the proposed method can produce susceptibility maps at a resolution higher than 1.8 × 1.8 × 2.4 mm3 along with metabolite spatiospectral distributions at a nominal spatial resolution of 2.4 × 2.4 × 2.4 mm3 from a single 7-min MRSI scan. The estimated susceptibility values are consistent with those obtained using the conventional QSM method with 3D multi-echo gradient echo acquisitions. This article reports a new capability for simultaneous susceptibility mapping and metabolic imaging of the brain from a single 1 H-MRSI scan, which has potential for a wide range of applications. Magn Reson Med 79:13-21, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017

  5. Nosologic imaging of the brain: segmentation and classification using MRI and MRSI.

    NARCIS (Netherlands)

    Luts, J.; Laudadio, T.; Idema, A.J.S.; Simonetti, A.W.; Heerschap, A.; Meulen, D. van der; Suykens, J.A.; Huffel, S. van

    2009-01-01

    A new technique is presented to create nosologic images of the brain based on magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI). A nosologic image summarizes the presence of different tissues and lesions in a single image by color coding each voxel or pixel

  6. SU-E-QI-21: Iodinated Contrast Agent Time Course In Human Brain Metastasis: A Study For Stereotactic Synchrotron Radiotherapy Clinical Trials

    Energy Technology Data Exchange (ETDEWEB)

    Obeid, L; Esteve, F; Adam, J [Grenoble Institut des Neurosciences, La Tronche, Isere (France); Tessier, A; Balosso, J [Centre Hospitalier Universitaire, La Tronche, Isere (France)

    2014-06-15

    Purpose: Synchrotron stereotactic radiotherapy (SSRT) is an innovative treatment combining the selective accumulation of heavy elements in tumors with stereotactic irradiations using monochromatic medium energy x-rays from a synchrotron source. Phase I/II clinical trials on brain metastasis are underway using venous infusion of iodinated contrast agents. The radiation dose enhancement depends on the amount of iodine in the tumor and its time course. In the present study, the reproducibility of iodine concentrations between the CT planning scan day (Day 0) and the treatment day (Day 10) was assessed in order to predict dose errors. Methods: For each of days 0 and 10, three patients received a biphasic intravenous injection of iodinated contrast agent (40 ml, 4 ml/s, followed by 160 ml, 0.5 ml/s) in order to ensure stable intra-tumoral amounts of iodine during the treatment. Two volumetric CT scans (before and after iodine injection) and a multi-slice dynamic CT of the brain were performed using conventional radiotherapy CT (Day 0) or quantitative synchrotron radiation CT (Day 10). A 3D rigid registration was processed between images. The absolute and relative differences of absolute iodine concentrations and their corresponding dose errors were evaluated in the GTV and PTV used for treatment planning. Results: The differences in iodine concentrations remained within the standard deviation limits. The 3D absolute differences followed a normal distribution centered at zero mg/ml with a variance (∼1 mg/ml) which is related to the image noise. Conclusion: The results suggest that dose errors depend only on the image noise. This study shows that stable amounts of iodine are achievable in brain metastasis for SSRT treatment in a 10 days interval.

  7. Pushing the sensitivity envelope of lanthanide-based magnetic resonance imaging (MRI) contrast agents for molecular imaging applications.

    Science.gov (United States)

    Aime, Silvio; Castelli, Daniela Delli; Crich, Simonetta Geninatti; Gianolio, Eliana; Terreno, Enzo

    2009-07-21

    Contrast in magnetic resonance imaging (MRI) arises from changes in the intensity of the proton signal of water between voxels (essentially, the 3D counterpart of pixels). Differences in intervoxel intensity can be significantly enhanced with chemicals that alter the nuclear magnetic resonance (NMR) intensity of the imaged spins; this alteration can occur by various mechanisms. Paramagnetic lanthanide(III) complexes are used in two major classes of MRI contrast agent: the well-established class of Gd-based agents and the emerging class of chemical exchange saturation transfer (CEST) agents. A Gd-based complex increases water signal by enhancing the longitudinal relaxation rate of water protons, whereas CEST agents decrease water signal as a consequence of the transfer of saturated magnetization from the exchangeable protons of the agent. In this Account, we survey recent progress in both areas, focusing on how MRI is becoming a more competitive choice among the various molecular imaging methods. Compared with other imaging modalities, MRI is set apart by its superb anatomical resolution; however, its success in molecular imaging suffers because of its intrinsic insensitivity. A relatively high concentration of molecular agents (0.01-0.1 mM) is necessary to produce a local alteration in the water signal intensity. Unfortunately, the most desirable molecules for visualization in molecular imaging are present at much lower concentrations, in the nano- or picomolar range. Therefore, augmenting the sensitivity of MRI agents is key to the development of MR-based molecular imaging applications. In principle, this task can be tackled either by increasing the sensitivity of the reporting units, through the optimization of their structural and dynamic properties, or by setting up proper amplification strategies that allow the accumulation of a huge number of imaging reporters at the site of interest. For Gd-based agents, high sensitivities can be attained by exploiting a

  8. Clinical trial design for systemic agents in patients with brain metastases from solid tumours: a guideline by the Response Assessment in Neuro-Oncology Brain Metastases working group.

    Science.gov (United States)

    Camidge, D Ross; Lee, Eudocia Q; Lin, Nancy U; Margolin, Kim; Ahluwalia, Manmeet S; Bendszus, Martin; Chang, Susan M; Dancey, Janet; de Vries, Elisabeth G E; Harris, Gordon J; Hodi, F Stephen; Lassman, Andrew B; Macdonald, David R; Peereboom, David M; Schiff, David; Soffietti, Ricardo; van den Bent, Martin J; Wefel, Jeffrey S; Wen, Patrick Y

    2018-01-01

    Patients with active CNS disease are often excluded from clinical trials, and data regarding the CNS efficacy of systemic agents are usually obtained late in the drug development process or not at all. In this guideline from the Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) working group, we provide detailed recommendations on when patients with brain metastases from solid tumours should be included or excluded in clinical trials of systemic agents. We also discuss the limitations of retrospective studies in determining the CNS efficacy of systemic drugs. Inclusion of patients with brain metastases early on in the clinical development of a drug or a regimen is needed to generate appropriate CNS efficacy or non-efficacy signals. We consider how to optimally incorporate or exclude such patients in systemic therapy trials depending on the likelihood of CNS activity of the agent by considering three scenarios: drugs that are considered very unlikely to have CNS antitumour activity or efficacy; drugs that are considered very likely to have CNS activity or efficacy; and drugs with minimal baseline information on CNS activity or efficacy. We also address trial design issues unique to patients with brain metastases, including the selection of appropriate CNS endpoints in systemic therapy trials. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. A quantitative MRI method for imaging blood-brain barrier leakage in experimental traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available Blood-brain barrier (BBB disruption is common following traumatic brain injury (TBI. Dynamic contrast enhanced (DCE MRI can longitudinally measure the transport coefficient Ktrans which reflects BBB permeability. Ktrans measurements however are not widely used in TBI research because it is generally considered to be noisy and possesses low spatial resolution. We improved spatiotemporal resolution and signal sensitivity of Ktrans MRI in rats by using a high-sensitivity surface transceiver coil. To overcome the signal drop off profile of the surface coil, a pre-scan module was used to map the flip angle (B1 field and magnetization (M0 distributions. A series of T1-weighted gradient echo images were acquired and fitted to the extended Kety model with reversible or irreversible leakage, and the best model was selected using F-statistics. We applied this method to study the rat brain one hour following controlled cortical impact (mild to moderate TBI, and observed clear depiction of the BBB damage around the impact regions, which matched that outlined by Evans Blue extravasation. Unlike the relatively uniform T2 contrast showing cerebral edema, Ktrans shows a pronounced heterogeneous spatial profile in and around the impact regions, displaying a nonlinear relationship with T2. This improved Ktrans MRI method is also compatible with the use of high-sensitivity surface coil and the high-contrast two-coil arterial spin-labeling method for cerebral blood flow measurement, enabling more comprehensive investigation of the pathophysiology in TBI.

  10. Classification of CT brain images based on deep learning networks.

    Science.gov (United States)

    Gao, Xiaohong W; Hui, Rui; Tian, Zengmin

    2017-01-01

    While computerised tomography (CT) may have been the first imaging tool to study human brain, it has not yet been implemented into clinical decision making process for diagnosis of Alzheimer's disease (AD). On the other hand, with the nature of being prevalent, inexpensive and non-invasive, CT does present diagnostic features of AD to a great extent. This study explores the significance and impact on the application of the burgeoning deep learning techniques to the task of classification of CT brain images, in particular utilising convolutional neural network (CNN), aiming at providing supplementary information for the early diagnosis of Alzheimer's disease. Towards this end, three categories of CT images (N = 285) are clustered into three groups, which are AD, lesion (e.g. tumour) and normal ageing. In addition, considering the characteristics of this collection with larger thickness along the direction of depth (z) (~3-5 mm), an advanced CNN architecture is established integrating both 2D and 3D CNN networks. The fusion of the two CNN networks is subsequently coordinated based on the average of Softmax scores obtained from both networks consolidating 2D images along spatial axial directions and 3D segmented blocks respectively. As a result, the classification accuracy rates rendered by this elaborated CNN architecture are 85.2%, 80% and 95.3% for classes of AD, lesion and normal respectively with an average of 87.6%. Additionally, this improved CNN network appears to outperform the others when in comparison with 2D version only of CNN network as well as a number of state of the art hand-crafted approaches. As a result, these approaches deliver accuracy rates in percentage of 86.3, 85.6 ± 1.10, 86.3 ± 1.04, 85.2 ± 1.60, 83.1 ± 0.35 for 2D CNN, 2D SIFT, 2D KAZE, 3D SIFT and 3D KAZE respectively. The two major contributions of the paper constitute a new 3-D approach while applying deep learning technique to extract signature information

  11. Carbon Dots as Nontoxic and High-Performance Fluorescence Imaging Agents

    OpenAIRE

    Yang, Sheng-Tao; Wang, Xin; Wang, Haifang; Lu, Fushen; Luo, Pengju G.; Cao, Li; Meziani, Mohammed J.; Liu, Jia-Hui; Liu, Yuanfang; Chen, Min; Huang, Yipu; Sun, Ya-Ping

    2009-01-01

    Fluorescent carbon dots (small carbon nanoparticles with the surface passivated by oligomeric PEG molecules) were evaluated for their cytotoxicity and in vivo toxicity and also for their optical imaging performance in reference to that of the commercially supplied CdSe/ZnS quantum dots. The results suggested that the carbon dots were biocompatible, and their performance as fluorescence imaging agents was competitive. The implication to the use of carbon dots for in vitro and in vivo applicati...

  12. Carbon Dots as Nontoxic and High-Performance Fluorescence Imaging Agents.

    Science.gov (United States)

    Yang, Sheng-Tao; Wang, Xin; Wang, Haifang; Lu, Fushen; Luo, Pengju G; Cao, Li; Meziani, Mohammed J; Liu, Jia-Hui; Liu, Yuanfang; Chen, Min; Huang, Yipu; Sun, Ya-Ping

    2009-09-28

    Fluorescent carbon dots (small carbon nanoparticles with the surface passivated by oligomeric PEG molecules) were evaluated for their cytotoxicity and in vivo toxicity and also for their optical imaging performance in reference to that of the commercially supplied CdSe/ZnS quantum dots. The results suggested that the carbon dots were biocompatible, and their performance as fluorescence imaging agents was competitive. The implication to the use of carbon dots for in vitro and in vivo applications is discussed.

  13. Functional Brain Imaging Synthesis Based on Image Decomposition and Kernel Modeling: Application to Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Francisco J. Martinez-Murcia

    2017-11-01

    Full Text Available The rise of neuroimaging in research and clinical practice, together with the development of new machine learning techniques has strongly encouraged the Computer Aided Diagnosis (CAD of different diseases and disorders. However, these algorithms are often tested in proprietary datasets to which the access is limited and, therefore, a direct comparison between CAD procedures is not possible. Furthermore, the sample size is often small for developing accurate machine learning methods. Multi-center initiatives are currently a very useful, although limited, tool in the recruitment of large populations and standardization of CAD evaluation. Conversely, we propose a brain image synthesis procedure intended to generate a new image set that share characteristics with an original one. Our system focuses on nuclear imaging modalities such as PET or SPECT brain images. We analyze the dataset by applying PCA to the original dataset, and then model the distribution of samples in the projected eigenbrain space using a Probability Density Function (PDF estimator. Once the model has been built, we can generate new coordinates on the eigenbrain space belonging to the same class, which can be then projected back to the image space. The system has been evaluated on different functional neuroimaging datasets assessing the: resemblance of the synthetic images with the original ones, the differences between them, their generalization ability and the independence of the synthetic dataset with respect to the original. The synthetic images maintain the differences between groups found at the original dataset, with no significant differences when comparing them to real-world samples. Furthermore, they featured a similar performance and generalization capability to that of the original dataset. These results prove that these images are suitable for standardizing the evaluation of CAD pipelines, and providing data augmentation in machine learning systems -e.g. in deep

  14. A generalized learning based framework for fast brain image registration.

    Science.gov (United States)

    Kim, Minjeong; Wu, Guorong; Yap, Pew-Thian; Shen, Dinggang

    2010-01-01

    This paper presents a generalized learning based framework for improving both speed and accuracy of the existing deformable registration method. The key of our framework involves the utilization of a support vector regression (SVR) to learn the correlation between brain image appearances and their corresponding shape deformations to a template, for helping significantly cut down the computation cost and improve the robustness to local minima by using the learned correlation to instantly predict a good subject-specific deformation initialization for any given subject under registration. Our framework consists of three major parts: 1) training of SVR models based on the statistics of image samples and their shape deformations to capture intrinsic image-deformation correlations, 2) deformation prediction for a new subject with the trained SVR models to generate a subject-resemblance intermediate template by warping the original template with the predicted deformations, and 3) estimating of the residual deformation from the intermediate template to the subject for refined registration. Any existing deformable registration methods can be easily employed for training the SVR models and estimating the residual deformation. We have tested in this paper the two widely used deformable registration algorithms, i.e., HAMMER] and diffeomorphic demons, for demonstration of our proposed frameowrk. Experimental results show that, compared to the registration using the original methods (with no deformation prediction), our framework achieves a significant speedup (6X faster than HAMMER, and 3X faster than diffeomorphic demons), while maintaining comparable (or even slighly better) registration accuracy.

  15. The Multimodal Brain Tumor Image Segmentation Benchmark (BRATS)

    Science.gov (United States)

    Jakab, Andras; Bauer, Stefan; Kalpathy-Cramer, Jayashree; Farahani, Keyvan; Kirby, Justin; Burren, Yuliya; Porz, Nicole; Slotboom, Johannes; Wiest, Roland; Lanczi, Levente; Gerstner, Elizabeth; Weber, Marc-André; Arbel, Tal; Avants, Brian B.; Ayache, Nicholas; Buendia, Patricia; Collins, D. Louis; Cordier, Nicolas; Corso, Jason J.; Criminisi, Antonio; Das, Tilak; Delingette, Hervé; Demiralp, Çağatay; Durst, Christopher R.; Dojat, Michel; Doyle, Senan; Festa, Joana; Forbes, Florence; Geremia, Ezequiel; Glocker, Ben; Golland, Polina; Guo, Xiaotao; Hamamci, Andac; Iftekharuddin, Khan M.; Jena, Raj; John, Nigel M.; Konukoglu, Ender; Lashkari, Danial; Mariz, José António; Meier, Raphael; Pereira, Sérgio; Precup, Doina; Price, Stephen J.; Raviv, Tammy Riklin; Reza, Syed M. S.; Ryan, Michael; Sarikaya, Duygu; Schwartz, Lawrence; Shin, Hoo-Chang; Shotton, Jamie; Silva, Carlos A.; Sousa, Nuno; Subbanna, Nagesh K.; Szekely, Gabor; Taylor, Thomas J.; Thomas, Owen M.; Tustison, Nicholas J.; Unal, Gozde; Vasseur, Flor; Wintermark, Max; Ye, Dong Hye; Zhao, Liang; Zhao, Binsheng; Zikic, Darko; Prastawa, Marcel; Reyes, Mauricio; Van Leemput, Koen

    2016-01-01

    In this paper we report the set-up and results of the Multimodal Brain Tumor Image Segmentation Benchmark (BRATS) organized in conjunction with the MICCAI 2012 and 2013 conferences. Twenty state-of-the-art tumor segmentation algorithms were applied to a set of 65 multi-contrast MR scans of low- and high-grade glioma patients—manually annotated by up to four raters—and to 65 comparable scans generated using tumor image simulation software. Quantitative evaluations revealed considerable disagreement between the human raters in segmenting various tumor sub-regions (Dice scores in the range 74%–85%), illustrating the difficulty of this task. We found that different algorithms worked best for different sub-regions (reaching performance comparable to human inter-rater variability), but that no single algorithm ranked in the top for all sub-regions simultaneously. Fusing several good algorithms using a hierarchical majority vote yielded segmentations that consistently ranked above all individual algorithms, indicating remaining opportunities for further methodological improvements. The BRATS image data and manual annotations continue to be publicly available through an online evaluation system as an ongoing benchmarking resource. PMID:25494501

  16. Magnetic resonance imaging of metastatic disease to the brain with gadobenate dimeglumine

    Energy Technology Data Exchange (ETDEWEB)

    Baleriaux, D. [Clinique de Neuroradiologie, Hopital Erasme, Brussels (Belgium); Colosimo, C. [Institute of Radiological Sciences, University G. d' Annunzio, Chieti (Italy); Ruscalleda, J. [Radiology Department, Hospital de San Pablo de Barcelona, Barcelona (Spain); Korves, M. [Institut fuer Roentgendiagnostik, Humboldt-Universitaet, Berlin (Germany); Schneider, G. [Department of Diagnostic Radiology, University Hospital, Homburg/Saar (Germany); Bohndorf, K. [Klinik fuer Diagnostische Radiologie und Neuroradiologie, Zentralklinikum Augsburg, Augsburg (Germany); Bongartz, G. [Departement Medizinische Radiologie, Universitaetsklinikum, Kantonsspital Basel, Basle (Switzerland); Buchem, M.A. van [Department of Diagnostic Radiology, University Hospital Leiden, Leiden (Netherlands); Reiser, M. [Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Radiologische Diagnostik-Klinikum Grosshadern, Munich (Germany); Sartor, K. [Universitaetsklinikum Heidelberg, Abteilung Neuroradiologie, Heidelberg (Germany); Bourne, M.W. [Department of Diagnostic Radiology, University Hospital of Wales, Cardiff, Wales (United Kingdom); Parizel, P.M. [Department of Radiology, Universitair Ziekenhuis Antwerpen, Edegem (Belgium); Cherryman, G.R. [Department of Diagnostic Radiology, University of Leicester School of Medicine, Leicester Royal Infirmary, Leicester (United Kingdom); Salerio, I.; Noce, La A.; Pirovano, G.; Kirchin, M.A.; Spinazzi, A. [Medical Affairs Europe, Milan (Italy)

    2002-03-01

    Seventy-four patients with one to eight proven intraaxial brain metastases received a total cumulative dose of 0.2 mmol/kg bodyweight gadobenate dimeglumine, administered as sequential injections of 0.05, 0.05 and 0.1 mmol/kg over a 20-min period. MR imaging was performed before the first administration (T2- and T1-weighted sequences) and after each injection of contrast agent (T1-weighted sequences only). Quantitative assessment of images revealed significant (P<0.01) dose-related increases in lesion-to-brain (L/B) ratio and percent enhancement of lesion signal intensity. Qualitative assessment by two independent, blinded assessors revealed additional lesions in 22%, 25% and 38% (assessor 1) and 29%, 32% and 34% (assessor 2) of patients after each cumulative dose when compared with combined T1- and T2-weighted pre-contrast images. Significantly more lesions (P{<=}0.01) were noted by both assessors after the first injection and by one assessor after each subsequent injection. For patients with just one lesion observed on unenhanced T1- and T2-weighted images, additional lesions were noted in 12%, 16% and 28% of patients by assessor 1 following each dose and in 24%, 27% and 30% of patients by assessor 2. Contemporaneously, diagnostic confidence was increased and lesion conspicuity improved over unenhanced MRI. For patients with one lesion observed after an initial dose of 0.05 mmol/kg, additional lesions were noted by assessors 1 and 2 in 9.1% and 11.8% of patients, respectively, after a cumulative dose of 0.1 mmol/kg and in a further 9.1% and 5.9% of patients, respectively, after a cumulative dose of 0.2 mmol/kg. No safety concerns were apparent. (orig.)

  17. {sup 11}C-labeled stilbene derivatives as A{beta}-aggregate-specific PET imaging agents for Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Masahiro; Wilson, Alan; Nobrega, Jose; Westaway, David; Verhoeff, Paul; Zhuang Zhiping; Kung Meiping; Kung, Hank F. E-mail: kunghf@sunmac.spect.upenn.edu

    2003-08-01

    A series of stilbene derivatives as potential diagnostic imaging agents targeting amyloid plaques in Alzheimer's disease (AD) were synthesized and evaluated. The syntheses of the stilbenes were successfully achieved by a simple Wadsworth-Emmons reaction between diethyl (4-nitrobenzyl)phosphonate and 4-methoxybenzaldehyde. 4-N,N-dimethylamino-4'-methyoxy and the corresponding 4-N-monomethylamino-, 4'-hydroxy stilbenes showed good binding affinities towards A{beta} aggregates in vitro (K{sub i} < 10 nM). The {sup 11}C labeled 4-N-methylamino-4'-hydroxystilbene, [{sup 11}C]4, was prepared by {sup 11}C methylation of 4-amino-4'-hydroxystilbene. The [{sup 11}C]4 displayed a moderate lipophilicity (log P = 2.36), and showed a very good brain penetration and washout from normal rat brain after an iv injection. In vitro autoradiography of transgenic AD mouse brain sections showed a high specific labeling of {beta}-amyloid plaques, whereas the control sections showed no binding. Taken together the data suggest that a relatively simple stilbene derivative, [{sup 11}C]4, N-[{sup 11}C]methylamino-4'-hydroxystilbene, may be useful as a positron emission tomography (PET) imaging agent for mapping A{beta} plaques in the brain of patients with Alzheimer's disease.

  18. The iconographic brain. A critical philosophical inquiry into (the resistance of) the image

    Science.gov (United States)

    De Vos, Jan

    2014-01-01

    The brain image plays a central role in contemporary image culture and, in turn, (co)constructs contemporary forms of subjectivity. The central aim of this paper is to probe the unmistakably potent interpellative power of brain images by delving into the power of imaging and the power of the image itself. This is not without relevance for the neurosciences, inasmuch as these do not take place in a vacuum; hence the importance of inquiring into the status of the image within scientific culture and science itself. I will mount a critical philosophical investigation of the brain qua image, focusing on the issue of mapping the mental onto the brain and how, in turn, the brain image plays a pivotal role in processes of subjectivation. Hereto, I draw upon Science & Technology Studies, juxtaposed with culture and ideology critique and theories of image culture. The first section sets out from Althusser's concept of interpellation, linking ideology to subjectivity. Doing so allows to spell out the central question of the paper: what could serve as the basis for a critical approach, or, where can a locus of resistance be found? In the second section, drawing predominantly on Baudrillard, I delve into the dimension of virtuality as this is opened up by brain image culture. This leads to the question of whether the digital brain must be opposed to old analog psychology: is it the psyche which resists? This issue is taken up in the third section which, ultimately, concludes that the psychological is not the requisite locus of resistance. The fourth section proceeds to delineate how the brain image is constructed from what I call the data-gaze (the claim that brain data are always already visual). In the final section, I discuss how an engagement with theories of iconology affords a critical understanding of the interpellative force of the brain image, which culminates in the somewhat unexpected claim that the sought after resistance lies in the very status of the image itself

  19. Associations of neighborhood environment with brain imaging outcomes in the Australian Imaging, Biomarkers and Lifestyle cohort.

    Science.gov (United States)

    Cerin, Ester; Rainey-Smith, Stephanie R; Ames, David; Lautenschlager, Nicola T; Macaulay, S Lance; Fowler, Christopher; Robertson, Joanne S; Rowe, Christopher C; Maruff, Paul; Martins, Ralph N; Masters, Colin L; Ellis, Kathryn A

    2017-04-01

    "Walkable" neighborhoods offer older adults opportunities for activities that may benefit cognition-related biological mechanisms. These have not previously been examined in this context. We objectively assessed neighborhood walkability for participants (n = 146) from the Australian Imaging, Biomarkers and Lifestyle study with apolipoprotein E (APOE) genotype and two 18-month-apart brain volumetric and/or amyloid β burden assessments. Linear mixed models estimated associations of neighborhood walkability with levels and changes in brain imaging outcomes, the moderating effect of APOE ε4 status, and the extent to which associations were explained by physical activity. Cross-sectionally, neighborhood walkability was predictive of better neuroimaging outcomes except for left hippocampal volume. These associations were to a small extent explained by physical activity. APOE ε4 carriers showed slower worsening of outcomes if living in walkable neighborhoods. These findings indicate associations between neighborhood walkability and brain imaging measures (especially in APOE ε4 carriers) minimally attributable to physical activity. Copyright © 2016 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  20. Examining multi-component DNA-templated nanostructures as imaging agents

    Science.gov (United States)

    Jaganathan, Hamsa

    2011-12-01

    Magnetic resonance imaging (MRI) is the leading non-invasive tool for disease imaging and diagnosis. Although MRI exhibits high spatial resolution for anatomical features, the contrast resolution is low. Imaging agents serve as an aid to distinguish different types of tissues within images. Gadolinium chelates, which are considered first generation designs, can be toxic to health, while ultra-small, superparamagnetic nanoparticles (NPs) have low tissue-targeting efficiency and rapid bio-distribution, resulting to an inadequate detection of the MRI signal and enhancement of image contrast. In order to improve the utility of MRI agents, the challenge in composition and structure needs to be addressed. One-dimensional (1D), superparamagnetic nanostructures have been reported to enhance magnetic and in vivo properties and therefore has a potential to improve contrast enhancement in MRI images. In this dissertation, the structure of 1D, multi-component NP chains, scaffolded on DNA, were pre-clinically examined as potential MRI agents. First, research was focused on characterizing and understanding the mechanism of proton relaxation for DNA-templated NP chains using nuclear magnetic resonance (NMR) spectrometry. Proton relaxation and transverse relaxivity were higher in multi-component NP chains compared to disperse NPs, indicating the arrangement of NPs on a 1D structure improved proton relaxation sensitivity. Second, in vitro evaluation for potential issues in toxicity and contrast efficiency in tissue environments using a 3 Tesla clinical MRI scanner was performed. Cell uptake of DNA-templated NP chains was enhanced after encapsulating the nanostructure with layers of polyelectrolytes and targeting ligands. Compared to dispersed NPs, DNA-templated NP chains improved MRI contrast in both the epithelial basement membrane and colon cancer tumors scaffolds. The last part of the project was focused on developing a novel MRI agent that detects changes in DNA methylation

  1. Recent Progress in Delivery of Therapeutic and Imaging Agents Utilizing Organic-inorganic Hybrid Nanoparticles.

    Science.gov (United States)

    Tanzina, Haque Sheikh; Chowdhury, Ezharul

    2017-11-19

    Delivery of conventional small molecule drugs and currently evolving nucleic acid-based therapeutics, such as small interfering RNAs (siRNAs) and genes, and contrast agents for high resolution imaging, to the target site of action is highly demanding to increase the therapeutic and imaging efficacy while minimizing the off-target effects of the delivered molecules, as well as develop novel therapeutic and imaging approaches. Organic-inorganic hybrid nanoparticles offer a number of advantages by combining the unique properties of the organic and inorganic counterparts, thus improving the pharmacokinetic behavior and targetability of drugs and contrast agents, and conferring the exclusive optical and magnetic properties for both therapeutic and imaging purposes. Different polymers, lipids, dendrimers, peptides, cell membranes, and small organic molecules were attached via covalent or non-covalent interactions with diverse inorganic nanoparticles of gold, mesoporous silica, magnetic iron oxide, carbon nanotubes and quantum dots for efficient drug delivery and imaging purposes. In this review, we highlight the progress made so far in utilizing different organic-inorganic hybrid nanoparticles for in vivo delivery of anti-cancer drugs, siRNA, genes and imaging agents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Technetium-99m Labeled Duramycin: A Novel Molecular Imaging Agent to Detect Apoptosis in Cardiovascular Pathologies

    Science.gov (United States)

    Chaudhry, Farhan

    Apoptosis underlines atherosclerosis and myocardial infarction/reperfusion (IR) injury. An imaging agent targeting apoptosis would increase the specificity of non-invasive imaging of apoptosis in these pathologies. Duramycin binds to phosphatidylethanolamine (PE) on the surface of apoptotic cells and can thus target apoptosis. In this study, technetium-99m labeled duramycin (TcD) was used to image both atherosclerosis and IR injury in rabbits using SPECT/CT. Rabbits were inflicted with atherosclerotic damage, IR injury, or were unmanipulated (control). Also, to assess for detection of therapeutic changes, a cardioprotective agent (minocycline) was used in IR rabbits. TcD, 99mTc-Annexin A5 (positive control), and linear TcD (Duramycin without the binding head to PE) were all imaged using SPECT/CT. Aortic or heart samples were collected with their respective organ samples for gamma counting and histopathology. After correlating the imaging, sample gamma counts, and the histopathology, TcD is a feasible imaging agent for apoptosis in atherosclerotic and IR injury.

  3. Microbubbles as x-ray scattering contrast agents using analyzer-based imaging

    Energy Technology Data Exchange (ETDEWEB)

    Arfelli, F [Department of Physics, University of Trieste, Via Valerio 2, 34127 Trieste (Italy); Rigon, L [Istituto Nazionale di Fisica Nucleare-Sezione di Trieste, Via Valerio 2, 34127 Trieste (Italy); Menk, R H [Sincrotrone Trieste S.C.p.A., Strada Statale 14-km 163.5 in AREA Science Park, 34012 Basovizza, Trieste (Italy)

    2010-03-21

    Conventional contrast agents utilized in diagnostic radiology are based on x-ray absorption properties; alternative physical principles capable of providing a contrast enhancement in radiographs have never been applied. This study exploits the possibility of using a novel type of contrast media based on x-ray scattering. The contrast agents consist of microbubble echo-enhancing agents, usually applied in ultrasound examinations, which are invisible with conventional x-ray absorption techniques. The experiment was carried out at the medical beamline of the synchrotron radiation laboratory ELETTRA in Trieste, Italy. A flat silicon analyzer crystal typically used for diffraction-enhanced imaging was utilized as a tool for detecting the scattering properties of the contrast agents. In analyzer-based imaging, it is possible to detect the scattering properties of the sample by shifting the analyzer crystal to selected positions of its reflectivity curve. In particular, when the sample consists of a large number of micro-particles an overall effect can be observed. Phantoms containing contrast agents based on microbubbles were imaged at different angular positions of the analyzer crystal. High visibility of the details was demonstrated, and a strong contrast enhancement was measured compared to normal x-ray absorption techniques.

  4. ViRPET--combination of virtual reality and PET brain imaging

    Energy Technology Data Exchange (ETDEWEB)

    Majewski, Stanislaw; Brefczynski-Lewis, Julie

    2017-05-23

    Various methods, systems and apparatus are provided for brain imaging during virtual reality stimulation. In one example, among others, a system for virtual ambulatory environment brain imaging includes a mobile brain imager configured to obtain positron emission tomography (PET) scans of a subject in motion, and a virtual reality (VR) system configured to provide one or more stimuli to the subject during the PET scans. In another example, a method for virtual ambulatory environment brain imaging includes providing stimulation to a subject through a virtual reality (VR) system; and obtaining a positron emission tomography (PET) scan of the subject while moving in response to the stimulation from the VR system. The mobile brain imager can be positioned on the subject with an array of imaging photodetector modules distributed about the head of the subject.

  5. External ventricular drain causes brain tissue damage: an imaging study.

    Science.gov (United States)

    Ortolano, Fabrizio; Carbonara, Marco; Stanco, Antonella; Civelli, Vittorio; Carrabba, Giorgio; Zoerle, Tommaso; Stocchetti, Nino

    2017-10-01

    An external ventricular drain (EVD) is used to measure intracranial pressure (ICP) and to drain cerebrospinal fluid (CSF). The procedure is generally safe, but parenchymal sequelae are reported as a possible side effect, with variable incidence. We investigated the mechanical sequelae of EVD insertion and their clinical significance in acute brain-injured patients, with a special focus on hemorrhagic lesions. Mechanical sequelae of EVD insertion were detected in patients by computed tomography (CT) and magnetic resonance imaging (MRI), performed for clinical purposes. In 155 patients we studied the brain tissue surrounding the EVD by CT scan (all patients) and MRI (16 patients); 53 patients were studied at three time points (day 1-2, day 3-10, >10 days after EVD placement) to document the lesion time course. Small hemorrhages, with a hyperdense core surrounded by a hypodense area, were identified by CT scan in 33 patients. The initial average (hyper- + hypodense) lesion volume was 8.16 ml, increasing up to 15 ml by >10 days after EVD insertion. These lesions were not accompanied by neurologic deterioration or ICP elevation. History of arterial hypertension, coagulation abnormalities and multiple EVD insertions were significantly associated with hemorrhages. In 122 non-hemorrhagic patients, we detected very small hypodense areas (average volume 0.38 ml) surrounding the catheter. At later times these hypodensities slightly increased. MRI studies in 16 patients identified both intra- and extracellular edema around the catheters. The extracellular component increased with time. EVD insertion, even when there are no clinically important complications, causes a tissue reaction with minimal bleedings and small areas of brain edema.

  6. RGD-based strategies for selective delivery of therapeutics and imaging agents to the tumour vasculature

    NARCIS (Netherlands)

    Temming, K; Molema, G; Kok, RJ

    2005-01-01

    During the past decade, RGD-peptides have become a popular tool for the targeting of drugs and imaging agents to a(v)beta(3)-integrin expressing tumour vasculature. RGD-peptides have been introduced by recombinant means into therapeutic proteins and viruses. Chemical means have been applied to

  7. Synthesis and biological evaluation of one novel technetium-99m-labeled nitroquipazine derivative as an imaging agent for serotonin transporter

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yunhang; Chen Xiangji; Jia Hongmei; Ji Xinmin [Key Laboratory of Radiopharmaceuticals (Beijing Normal University), Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875 (China); Liu Boli [Key Laboratory of Radiopharmaceuticals (Beijing Normal University), Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875 (China)], E-mail: liuboli@bnu.edu.cn

    2008-12-15

    Imaging of serotonin transporter (SERT) by positron emission tomography (PET) or single-photon emission-computed tomography (SPECT) in humans would provide useful information in diagnosis and therapy of several neurodegenerative and neuropsychiatric disorders. 6-Nitroquipazine is a highly potent and selective inhibitor of the SERT. For the development of new {sup 99m}Tc-labeled 6-nitroquipazine derivatives as SERT imaging agents, novel [N-[2-((3-(4-(6-nitroquinolin-2-yl)piperazin-1-yl)propyl)(2-mercaptoethyl) amino]-acetyl-2-aminoethanethiolato] [{sup 99m}Tc]technetium (V) oxide ({sup 99m}Tc-MAMA-3-PQ) and its rhenium analog were synthesized and characterized. {sup 99m}Tc-MAMA-3-PQ displayed high initial brain uptake (0.52% ID/organ at 2 min post-injection (pi)) and relatively fast washout in mice (0.09% ID/organ at 60 min pi). The regional brain distribution studies in rats showed high-specific binding ratios at 60 min pi. Maximum regional contrast ratio observed for thalamus/cerebellum was 2.94, followed by 2.62 for hypothalamus/cerebellum. These encouraging results lead us to further explore its derivatives as new imaging agents for the SERT in the brain.

  8. Imaging Plasmodium Immunobiology in Liver, Brain, and Lung

    Science.gov (United States)

    Frevert, Ute; Nacer, Adéla; Cabrera, Mynthia; Movila, Alexandru; Leberl, Maike

    2013-01-01

    Plasmodium falciparum malaria is responsible for the deaths of over half a million African children annually. Until a decade ago, dynamic analysis of the malaria parasite was limited to in vitro systems with the typical limitations associated with 2D monocultures or entirely artificial surfaces. Due to extremely low parasite densities, the liver was considered a black box in terms of Plasmodium sporozoite invasion, liver stage development, and merozoite release into the blood. Further, nothing was known about the behavior of blood stage parasites in organs such as brain where clinical signs manifest and the ensuing immune response of the host that may ultimately result in a fatal outcome. The advent of fluorescent parasites, advances in imaging technology, and availability of an ever-increasing number of cellular and molecular probes have helped illuminate many steps along the pathogenetic cascade of this deadly tropical parasite. PMID:24076429

  9. Imaging Plasmodium immunobiology in the liver, brain, and lung.

    Science.gov (United States)

    Frevert, Ute; Nacer, Adéla; Cabrera, Mynthia; Movila, Alexandru; Leberl, Maike

    2014-02-01

    Plasmodium falciparum malaria is responsible for the deaths of over half a million African children annually. Until a decade ago, dynamic analysis of the malaria parasite was limited to in vitro systems with the typical limitations associated with 2D monocultures or entirely artificial surfaces. Due to extremely low parasite densities, the liver was considered a black box in terms of Plasmodium sporozoite invasion, liver stage development, and merozoite release into the blood. Further, nothing was known about the behavior of blood stage parasites in organs such as the brain where clinical signs manifest and the ensuing immune response of the host that may ultimately result in a fatal outcome. The advent of fluorescent parasites, advances in imaging technology, and availability of an ever-increasing number of cellular and molecular probes have helped illuminate many steps along the pathogenetic cascade of this deadly tropical parasite. © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Apparatus and method for motion tracking in brain imaging

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is apparatus and method for motion tracking of a subject in medical brain imaging. The method comprises providing a light projector and a first camera; projecting a first pattern sequence (S1) onto a surface region of the subject with the light projector, wherein the subject is positioned...... in a scanner borehole of a medical scanner, the first pattern sequence comprising a first primary pattern (P1,1) and/or a first secondary pattern (P1,2); detecting the projected first pattern sequence (S1') with the first camera; determining a second pattern sequence (S2) comprising a second primary pattern (P......2,1) based on the detected first pattern sequence (S1'); projecting the second pattern sequence (S2) onto a surface region of the subject with the light projector; detecting the projected second pattern sequence (S2') with the first camera; and determining motion tracking parameters based...

  11. Memory networks in tinnitus: a functional brain image study.

    Science.gov (United States)

    Laureano, Maura Regina; Onishi, Ektor Tsuneo; Bressan, Rodrigo Affonseca; Castiglioni, Mario Luiz Vieira; Batista, Ilza Rosa; Reis, Marilia Alves; Garcia, Michele Vargas; de Andrade, Adriana Neves; de Almeida, Roberta Ribeiro; Garrido, Griselda J; Jackowski, Andrea Parolin

    2014-01-01

    Tinnitus is characterized by the perception of sound in the absence of an external auditory stimulus. The network connectivity of auditory and non-auditory brain structures associated with emotion, memory and attention are functionally altered in debilitating tinnitus. Current studies suggest that tinnitus results from neuroplastic changes in the frontal and limbic temporal regions. The objective of this study was to use Single-Photon Emission Computed Tomography (SPECT) to evaluate changes in the cerebral blood flow in tinnitus patients with normal hearing compared with healthy controls. Twenty tinnitus patients with normal hearing and 17 healthy controls, matched for sex, age and years of education, were subjected to Single Photon Emission Computed Tomography using the radiotracer ethylenedicysteine diethyl ester, labeled with Technetium 99 m (99 mTc-ECD SPECT). The severity of tinnitus was assessed using the "Tinnitus Handicap Inventory" (THI). The images were processed and analyzed using "Statistical Parametric Mapping" (SPM8). A significant increase in cerebral perfusion in the left parahippocampal gyrus (pFWE <0.05) was observed in patients with tinnitus compared with healthy controls. The average total THI score was 50.8+18.24, classified as moderate tinnitus. It was possible to identify significant changes in the limbic system of the brain perfusion in tinnitus patients with normal hearing, suggesting that central mechanisms, not specific to the auditory pathway, are involved in the pathophysiology of symptoms, even in the absence of clinically diagnosed peripheral changes.

  12. Memory networks in tinnitus: a functional brain image study.

    Directory of Open Access Journals (Sweden)

    Maura Regina Laureano

    Full Text Available Tinnitus is characterized by the perception of sound in the absence of an external auditory stimulus. The network connectivity of auditory and non-auditory brain structures associated with emotion, memory and attention are functionally altered in debilitating tinnitus. Current studies suggest that tinnitus results from neuroplastic changes in the frontal and limbic temporal regions. The objective of this study was to use Single-Photon Emission Computed Tomography (SPECT to evaluate changes in the cerebral blood flow in tinnitus patients with normal hearing compared with healthy controls.Twenty tinnitus patients with normal hearing and 17 healthy controls, matched for sex, age and years of education, were subjected to Single Photon Emission Computed Tomography using the radiotracer ethylenedicysteine diethyl ester, labeled with Technetium 99 m (99 mTc-ECD SPECT. The severity of tinnitus was assessed using the "Tinnitus Handicap Inventory" (THI. The images were processed and analyzed using "Statistical Parametric Mapping" (SPM8.A significant increase in cerebral perfusion in the left parahippocampal gyrus (pFWE <0.05 was observed in patients with tinnitus compared with healthy controls. The average total THI score was 50.8+18.24, classified as moderate tinnitus.It was possible to identify significant changes in the limbic system of the brain perfusion in tinnitus patients with normal hearing, suggesting that central mechanisms, not specific to the auditory pathway, are involved in the pathophysiology of symptoms, even in the absence of clinically diagnosed peripheral changes.

  13. Probabilistic brain tissue segmentation in neonatal magnetic resonance imaging.

    Science.gov (United States)

    Anbeek, Petronella; Vincken, Koen L; Groenendaal, Floris; Koeman, Annemieke; van Osch, Matthias J P; van der Grond, Jeroen

    2008-02-01

    A fully automated method has been developed for segmentation of four different structures in the neonatal brain: white matter (WM), central gray matter (CEGM), cortical gray matter (COGM), and cerebrospinal fluid (CSF). The segmentation algorithm is based on information from T2-weighted (T2-w) and inversion recovery (IR) scans. The method uses a K nearest neighbor (KNN) classification technique with features derived from spatial information and voxel intensities. Probabilistic segmentations of each tissue type were generated. By applying thresholds on these probability maps, binary segmentations were obtained. These final segmentations were evaluated by comparison with a gold standard. The sensitivity, specificity, and Dice similarity index (SI) were calculated for quantitative validation of the results. High sensitivity and specificity with respect to the gold standard were reached: sensitivity >0.82 and specificity >0.9 for all tissue types. Tissue volumes were calculated from the binary and probabilistic segmentations. The probabilistic segmentation volumes of all tissue types accurately estimated the gold standard volumes. The KNN approach offers valuable ways for neonatal brain segmentation. The probabilistic outcomes provide a useful tool for accurate volume measurements. The described method is based on routine diagnostic magnetic resonance imaging (MRI) and is suitable for large population studies.

  14. Hypnosis and imaging of the living human brain.

    Science.gov (United States)

    Landry, Mathieu; Raz, Amir

    2015-01-01

    Over more than two decades, studies using imaging techniques of the living human brain have begun to explore the neural correlates of hypnosis. The collective findings provide a gripping, albeit preliminary, account of the underlying neurobiological mechanisms involved in hypnotic phenomena. While substantial advances lend support to different hypotheses pertaining to hypnotic modulation of attention, control, and monitoring processes, the complex interactions among the many mediating variables largely hinder our ability to isolate robust commonalities across studies. The present account presents a critical integrative synthesis of neuroimaging studies targeting hypnosis as a function of suggestion. Specifically, hypnotic induction without task-specific suggestion is examined, as well as suggestions concerning sensation and perception, memory, and ideomotor response. The importance of carefully designed experiments is highlighted to better tease apart the neural correlates that subserve hypnotic phenomena. Moreover, converging findings intimate that hypnotic suggestions seem to induce specific neural patterns. These observations propose that suggestions may have the ability to target focal brain networks. Drawing on evidence spanning several technological modalities, neuroimaging studies of hypnosis pave the road to a more scientific understanding of a dramatic, yet largely evasive, domain of human behavior.

  15. Functional brain imaging predicts public health campaign success.

    Science.gov (United States)

    Falk, Emily B; O'Donnell, Matthew Brook; Tompson, Steven; Gonzalez, Richard; Dal Cin, Sonya; Strecher, Victor; Cummings, Kenneth Michael; An, Lawrence

    2016-02-01

    Mass media can powerfully affect health decision-making. Pre-testing through focus groups or surveys is a standard, though inconsistent, predictor of effectiveness. Converging evidence demonstrates that activity within brain systems associated with self-related processing can predict individual behavior in response to health messages. Preliminary evidence also suggests that neural activity in small groups can forecast population-level campaign outcomes. Less is known about the psychological processes that link neural activity and population-level outcomes, or how these predictions are affected by message content. We exposed 50 smokers to antismoking messages and used their aggregated neural activity within a 'self-localizer' defined region of medial prefrontal cortex to predict the success of the same campaign messages at the population level (n = 400,000 emails). Results demonstrate that: (i) independently localized neural activity during health message exposure complements existing self-report data in predicting population-level campaign responses (model combined R(2) up to 0.65) and (ii) this relationship depends on message content-self-related neural processing predicts outcomes in response to strong negative arguments against smoking and not in response to compositionally similar neutral images. These data advance understanding of the psychological link between brain and large-scale behavior and may aid the construction of more effective media health campaigns. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  16. Magnetic resonance imaging safety of deep brain stimulator devices.

    Science.gov (United States)

    Oluigbo, Chima O; Rezai, Ali R

    2013-01-01

    Magnetic resonance imaging (MRI) has become the standard of care for the evaluation of different neurological disorders of the brain and spinal cord due to its multiplanar capabilities and excellent soft tissue resolution. With the large and increasing population of patients with implanted deep brain stimulation (DBS) devices, a significant proportion of these patients with chronic neurological diseases require evaluation of their primary neurological disease processes by MRI. The presence of an implanted DBS device in a magnetic resonance environment presents potential hazards. These include the potential for induction of electrical currents or heating in DBS devices, which can result in neurological tissue injury, magnetic field-induced device migration, or disruption of the operational aspects of the devices. In this chapter, we review the basic physics of potential interactions of the MRI environment with implanted DBS devices, summarize results from phantom studies and clinical series, and discuss present recommendations for safe MRI in patients with implanted DBS devices. © 2013 Elsevier B.V. All rights reserved.

  17. PET imaging in the surgical management of pediatric brain tumors.

    Science.gov (United States)

    Pirotte, Benoit; Acerbi, Francesco; Lubansu, Alphonse; Goldman, Serge; Brotchi, Jacques; Levivier, Marc

    2007-07-01

    The present article illustrates whether positron-emission tomography (PET) imaging may improve the surgical management of pediatric brain tumors (PBT) at different steps. Among 400 consecutive PBT treated between 1995 and 2005 at Erasme Hospital, Brussels, Belgium, we have studied with (18) F-2-fluoro-2-deoxy-D-glucose (FDG)-PET and/or L-(methyl-(11)C)methionine (MET)-PET and integrated PET images in the diagnostic workup of 126 selected cases. The selection criteria were mainly based on the lesion appearance on magnetic resonance (MR) sequences. Cases were selected when MR imaging showed limitations for (1) assessing the evolving nature of an incidental lesion (n = 54), (2) selecting targets for contributive and accurate biopsy (n = 32), and (3) delineating tumor tissue for maximal resection (n = 40). Whenever needed, PET images were integrated in the planning of image-guided surgical procedures (frame-based stereotactic biopsies (SB), frameless navigation-based resections, or leksell gamma knife radiosurgery). Like in adults, PET imaging really helped the surgical management of the 126 children explored, which represented about 30% of all PBT, especially when the newly diagnosed brain lesion was (1) an incidental finding so that the choice between surgery and conservative MR follow-up was debated, and (2) so infiltrative or ill-defined on MR that the choice between biopsy and resection was hardly discussed. Integrating PET into the diagnostic workup of these two selected groups helped to (1) take a more appropriate decision in incidental lesions by detecting tumor/evolving tissue; (2) better understand complex cases by differentiating indolent and active components of the lesion; (3) improve target selection and diagnostic yield of stereotactic biopsies in gliomas; (4) illustrate the intratumoral histological heterogeneity in gliomas; (5) provide additional prognostic information; (6) reduce the number of trajectories in biopsies performed in eloquent areas such

  18. Developing a multiscale, multi-resolution agent-based brain tumor model by graphics processing units

    Science.gov (United States)

    2011-01-01

    Multiscale agent-based modeling (MABM) has been widely used to simulate Glioblastoma Multiforme (GBM) and its progression. At the intracellular level, the MABM approach employs a system of ordinary differential equations to describe quantitatively specific intracellular molecular pathways that determine phenotypic switches among cells (e.g. from migration to proliferation and vice versa). At the intercellular level, MABM describes cell-cell interactions by a discrete module. At the tissue level, partial differential equations are employed to model the diffusion of chemoattractants, which are the input factors of the intracellular molecular pathway. Moreover, multiscale analysis makes it possible to explore the molecules that play important roles in determining the cellular phenotypic switches that in turn drive the whole GBM expansion. However, owing to limited computational resources, MABM is currently a theoretical biological model that uses relatively coarse grids to simulate a few cancer cells in a small slice of brain cancer tissue. In order to improve this theoretical model to simulate and predict actual GBM cancer progression in real time, a graphics processing unit (GPU)-based parallel computing algorithm was developed and combined with the multi-resolution design to speed up the MABM. The simulated results demonstrated that the GPU-based, multi-resolution and multiscale approach can accelerate the previous MABM around 30-fold with relatively fine grids in a large extracellular matrix. Therefore, the new model has great potential for simulating and predicting real-time GBM progression, if real experimental data are incorporated. PMID:22176732

  19. Using Functional Magnetic Resonance Imaging to Detect Preserved Function in a Preterm Infant with Brain Injury.

    Science.gov (United States)

    Herzmann, Charlotte; Zubiaurre-Elorza, Leire; Wild, Conor J; Linke, Annika C; Han, Victor K; Lee, David S C; Cusack, Rhodri

    2017-10-01

    We studied developmental plasticity using functional magnetic resonance imaging (fMRI) in a preterm infant with brain injury on structural MRI. fMRI showed preserved brain function and subsequent neurodevelopment was within the normal range. Multimodal neuroimaging including fMRI can improve understanding of neural plasticity after preterm birth and brain injury. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Comparison of Magnetic Resonance Imaging in Live vs. Post Mortem Rat Brains

    Science.gov (United States)

    Oguz, Ipek; Yaxley, Richard; Budin, Francois; Hoogstoel, Marion; Lee, Joohwi; Maltbie, Eric; Liu, Wen; Crews, Fulton T.

    2013-01-01

    Magnetic Resonance Imaging (MRI) is an increasingly popular technique for examining neurobiology in rodents because it is both noninvasive and nondestructive. MRI scans can be acquired from either live or post mortem specimens. In vivo scans have a key advantage in that subjects can be scanned at multiple time-points in longitudinal studies. However, repeated exposure to anesthesia and stress may confound studies. In contrast, post mortem scans offer improved image quality and increased signal-to-noise ratio (SNR) due to several key advantages: First, the images are not disrupted by motion and pulsation artifacts. Second, they allow the brain tissue to be perfused with contrast agents, enhancing tissue contrast. Third, they allow longer image acquisition times, yielding higher resolution and/or improved SNR. Fourth, they allow assessment of groups of animals at the same age without scheduling complications. Despite these advantages, researchers are often skeptical of post mortem MRI scans because of uncertainty about whether the fixation process alters the MRI measurements. To address these concerns, we present a thorough comparative study of in vivo and post mortem MRI scans in healthy male Wistar rats at three age points throughout adolescence (postnatal days 28 through 80). For each subject, an in vivo scan was acquired, followed by perfusion and two post mortem scans at two different MRI facilities. The goal was to assess robustness of measurements, to detect any changes in volumetric measurements after fixation, and to investigate any differential bias that may exist between image acquisition techniques. We present this volumetric analysis for comparison of 22 anatomical structures between in vivo and post mortem scans. No significant changes in volumetric measurements were detected; however, as hypothesized, the image quality is dramatically improved in post mortem scans. These findings illustrate the validity and utility of using post mortem scans in

  1. Responsive magnetic resonance imaging contrast agents as chemical sensors for metals in biology and medicine.

    Science.gov (United States)

    Que, Emily L; Chang, Christopher J

    2010-01-01

    This tutorial review highlights progress in the development of responsive magnetic resonance imaging (MRI) contrast agents for detecting and sensing biologically relevant metal ions. Molecular imaging with bioactivatable MRI indicators offers a potentially powerful methodology for studying the physiology and pathology of metals by capturing dynamic three-dimensional images of living systems for research and clinical applications. This emerging area at the interface of inorganic chemistry and the life sciences offers a broad palette of opportunities for researchers with interests ranging from coordination chemistry and spectroscopy to supramolecular chemistry and molecular recognition to metals in biology and medicine.

  2. Magnetic resonance imaging and cell-based neurorestorative therapy after brain injury

    Directory of Open Access Journals (Sweden)

    Quan Jiang

    2016-01-01

    Full Text Available Restorative cell-based therapies for experimental brain injury, such as stroke and traumatic brain injury, substantially improve functional outcome. We discuss and review state of the art magnetic resonance imaging methodologies and their applications related to cell-based treatment after brain injury. We focus on the potential of magnetic resonance imaging technique and its associated challenges to obtain useful new information related to cell migration, distribution, and quantitation, as well as vascular and neuronal remodeling in response to cell-based therapy after brain injury. The noninvasive nature of imaging might more readily help with translation of cell-based therapy from the laboratory to the clinic.

  3. 5-HT radioligands for human brain imaging with PET and SPECT

    DEFF Research Database (Denmark)

    Paterson, Louise M; Kornum, Birgitte R; Nutt, David J

    2013-01-01

    The serotonergic system plays a key modulatory role in the brain and is the target for many drug treatments for brain disorders either through reuptake blockade or via interactions at the 14 subtypes of 5-HT receptors. This review provides the history and current status of radioligands used...... for positron emission tomography (PET) and single photon emission computerized tomography (SPECT) imaging of human brain serotonin (5-HT) receptors, the 5-HT transporter (SERT), and 5-HT synthesis rate. Currently available radioligands for in vivo brain imaging of the 5-HT system in humans include antagonists...... to image serotonergic targets is of high interest, and successful evaluation in humans is leading to invaluable insight into normal and abnormal brain function, emphasizing the need for continued development of both SPECT and PET radioligands for human brain imaging....

  4. Measurement of brain oxygenation changes using dynamic T1-weighted imaging

    DEFF Research Database (Denmark)

    Haddock, Bryan; Larsson, Henrik B W; Hansen, Adam E

    2013-01-01

    Magnetic resonance imaging (MRI) has proven useful in evaluating oxygenation in several types of tissue and blood. This study evaluates brain tissue oxygenation changes between normoxia and hyperoxia in healthy subjects using dynamic T1 and T2*-weighted imaging sequences. The change in FiO2 induced...... in the brain with a potential to provide quantitative information on tissue oxygenation....

  5. Value of C-11-methionine PET in imaging brain tumours and metastases

    NARCIS (Netherlands)

    Glaudemans, Andor W J M; Enting, Roeline; Heesters, Martinus; Dierckx, Rudi A J O; van Rheenen, Ronald W J; Walenkamp, Annemiek M E; Slart, Riemer H J A

    C-11-methionine (MET) is the most popular amino acid tracer used in PET imaging of brain tumours. Because of its characteristics, MET PET provides a high detection rate of brain tumours and good lesion delineation. This review focuses on the role of MET PET in imaging cerebral gliomas. The

  6. Seeing Is Believing: The Effect of Brain Images on Judgments of Scientific Reasoning

    Science.gov (United States)

    McCabe, David P.; Castel, Alan D.

    2008-01-01

    Brain images are believed to have a particularly persuasive influence on the public perception of research on cognition. Three experiments are reported showing that presenting brain images with articles summarizing cognitive neuroscience research resulted in higher ratings of scientific reasoning for arguments made in those articles, as compared…

  7. Bjork-Shiley convexoconcave valves: Susceptibility artifacts at brain MR imaging and mechanical valve fractures

    NARCIS (Netherlands)

    van Gorp, Maarten J.; van der Graaf, Yolanda; de Mol, Bas A. J. M.; Bakker, Chris J. G.; Witkamp, Theo D.; Ramos, Lino M. P.; Mali, Willem P. T. M.

    2004-01-01

    PURPOSE: To assess the relationship between heart valve history and susceptibility artifacts at magnetic resonance (MR) imaging of the brain in patients with Bjork-Shiley convexoconcave (BSCC) valves. MATERIALS AND METHODS: MR images of the brain were obtained in 58 patients with prosthetic heart

  8. A New Measure of Imagination Ability: Anatomical Brain Imaging Correlates.

    Science.gov (United States)

    Jung, Rex E; Flores, Ranee A; Hunter, Dan

    2016-01-01

    Imagination involves episodic memory retrieval, visualization, mental simulation, spatial navigation, and future thinking, making it a complex cognitive construct. Prior studies of imagination have attempted to study various elements of imagination (e.g., visualization), but none have attempted to capture the entirety of imagination ability in a single instrument. Here we describe the Hunter Imagination Questionnaire (HIQ), an instrument designed to assess imagination over an extended period of time, in a naturalistic manner. We hypothesized that the HIQ would be related to measures of creative achievement and to a network of brain regions previously identified to be important to imagination/creative abilities. Eighty subjects were administered the HIQ in an online format; all subjects were administered a broad battery of tests including measures of intelligence, personality, and aptitude, as well as structural Magnetic Resonance Imaging (sMRI). Responses of the HIQ were found to be normally distributed, and exploratory factor analysis yielded four factors. Internal consistency of the HIQ ranged from 0.76 to 0.79, and two factors ("Implementation" and "Learning") were significantly related to measures of Creative Achievement (Scientific-r = 0.26 and Writing-r = 0.31, respectively), suggesting concurrent validity. We found that the HIQ and its factors were related to a broad network of brain volumes including increased bilateral hippocampi, lingual gyrus, and caudal/rostral middle frontal lobe, and decreased volumes within the nucleus accumbens and regions within the default mode network (e.g., precuneus, posterior cingulate, transverse temporal lobe). The HIQ was found to be a reliable and valid measure of imagination in a cohort of normal human subjects, and was related to brain volumes previously identified as central to imagination including episodic memory retrieval (e.g., hippocampus). We also identified compelling evidence suggesting imagination ability

  9. A New Measure of Imagination Ability: Anatomical Brain Imaging Correlates

    Directory of Open Access Journals (Sweden)

    Rex Eugene Jung

    2016-04-01

    Full Text Available Imagination involves episodic memory retrieval, visualization, mental simulation, spatial navigation, and future thinking, making it a complex cognitive construct. Prior studies of imagination have attempted to study various elements of imagination (e.g., visualization, but none have attempted to capture the entirety of imagination ability in a single instrument. Here we describe the Hunter Imagination Questionnaire (HIQ, an instrument designed to assess imagination over an extended period of time, in a naturalistic manner. We hypothesized that the HIQ would be related to measures of creative achievement and to a network of brain regions previously identified to be important to imagination/creative abilities. Eighty subjects were administered the HIQ in an online format; all subjects were administered a broad battery of tests including measures of intelligence, personality, and aptitude, as well as structural Magnetic Resonance Imaging (sMR. Responses of the HIQ were found to be normally distributed, and exploratory factor analysis yielded four factors. Internal consistency of the HIQ ranged from .76 to .79, and two factors (Implementation and Learning were significantly related to measures of Creative Achievement (Scientifific - r = .26 and Writing - r = .31 respectively, suggesting concurrent validity. We found that the HIQ and its factors were related to a broad network of brain volumes including increased bilateral hippocampi, lingual gyrus, and caudal/rostral middle frontal lobe, and decreased volumes within the nucleus accumbens and regions within the default mode network (e.g., precuneus, posterior cingulate, transverse temporal lobe. The HIQ was found to be a reliable and valid measure of imagination in a cohort of normal human subjects, and was related to brain volumes previously identified as central to imagination including episodic memory retrieval (e.g., hippocampus. We also identified compelling evidence suggesting imagination

  10. Quantification and Assessment of the Chemical Form of Residual Gadolinium in the Brain After Repeated Administration of Gadolinium-Based Contrast Agents

    Science.gov (United States)

    Frenzel, Thomas; Apte, Chirag; Jost, Gregor; Schöckel, Laura; Lohrke, Jessica; Pietsch, Hubertus

    2017-01-01

    the soluble fraction was comparable to the macrocyclic agents. According to GPC, a smaller portion of the Gd in the soluble fraction of the linear GBCAs groups was bound to macromolecules larger than 250 to 300 kDa. The nature of the Gd-containing macromolecules and the insoluble species were not determined, but they appeared to be saturable with Gd. The excretion of the soluble Gd species in the linear and macrocyclic GBCA groups was still ongoing between days 3 and 24 p.i. This was also observed for the macromolecular Gd species in the linear GBCA groups, but at a slower rate. Conclusions The residual Gd found in the rat brain after repeated administration of all 3 linear GBCAs was present in at least 3 distinctive forms—soluble small molecules, including the intact GBCA, soluble macromolecules, and to a large extent in insoluble form. The latter 2 are most likely responsible for the prolonged signal intensity enhancement in brain structures observed in magnetic resonance imaging. No relevant differences between the 3 linear GBCAs were observed. The Gd concentrations in the brain after administration of macrocyclic GBCAs are lower, and the Gd is only present in soluble small molecules, which were slowly excreted. This underlines the crucial importance of the kinetic inertness of macrocyclic agents in the prevention of potential retention of Gd in the brain compared with the 3 linear, kinetically less restricted GBCAs. PMID:28125438

  11. Imaging findings of the brain abnormalities in acute lymphoblastic leukemia of children during and after treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Joo; Lee, Seung Rho; Park, Dong Woo; Joo, Kyung Bin; Kim, Jang Wook; Hahm, Chang Kok; Kim, Ki Joong; Lee, Hahng [College of Medicine, Hanyang Univ., Seoul (Korea, Republic of)

    2001-09-01

    We evaluated the imaging abnormalities of the brain observed during and after treatment of acute childhood lymphoblastic leukemia. The study group consisted of 30 patients (male : female=19 : 11 ; mean age, 64 months) with acute childhood lymphoblastic leukemia during the previous ten-year period who had undergone prophylaxis of the central nervous system. Irrespective of the CNS symptoms, base-line study of the brain involving CT and follow-up CT or MRI was undertaken more than once. We retrospectively evaluated the imaging findings, methods of treatment, associated CNS symptoms, and the interval between diagnosis and the time at which brain abnormalities were revealed by imaging studies. In 15 (50% ; male : female=9 : 6 ; mean age, 77 months) of 30 patients, brain abnormalities that included brain atrophy (n=9), cerebral infarctions (n=4), intracranial hemorrhage (n=1), mineralizing microangiopathy (n=2), and periventricular leukomalacia (n=3) were seen on follow-up CT or MR images. In four of nine patients with brain atrophy, imaging abnormalities such as periventricular leukomalacia (n=2), infarction (n=1) and microangiopathy (n=1) were demonstrated. Fourteen of the 15 patients underwent similar treatment ; the one excluded had leukemic cells in the CSF. Six patients had CNS symptoms. In the 15 patients with abnormal brain imaging findings, the interval between diagnosis and the demonstration of brain abnormalities was between one month and four years. After the cessation of treatment, imaging abnormalities remained in all patients except one with brain atrophy. Various imaging abnormalities of the brain may be seen during and after the treatment of acute childhood lymphoblastic leukemia and persist for a long time. In children with this condition, the assessment of brain abnormalities requires follow-up study of the brain.

  12. Infectious diseases of the brain: imaging and differential diagnosis; Infektioese Hirnerkrankungen: Bildgebung und differenzialdiagnostische Aspekte

    Energy Technology Data Exchange (ETDEWEB)

    Haehnel, S.; Seitz, A. [Abt. Neuroradiologie, Neurologische Klinik, Universitaetsklinikum Heidelberg (Germany); Storch-Hagenlocher, B. [Abt. Neurologie, Neurologische Klinik, Universitaetsklinikum Heidelberg (Germany)

    2006-09-15

    Infectious diseases of the central nervous system have to be considered in differential diagnosis particularly in immunocompromised persons. Neuro-imaging, specifically advanced techniques such as diffusion weighted MRI and perfusion MRI contribute much to the differentiation of brain infections and for differentiating brain infections from other, for instance, neoplastic diseases. In this review we present the imaging criteria of the most important brains infections in adults and in pediatric patients and discuss differential diagnostic aspects in detail. (orig.)

  13. Deep-red polymer dots with bright two-photon fluorescence and high biocompatibility for in vivo mouse brain imaging

    Science.gov (United States)

    Alifu, Nuernisha; Sun, Zezhou; Zebibula, Abudureheman; Zhu, Zhenggang; Zhao, Xinyuan; Wu, Changfeng; Wang, Yalun; Qian, Jun

    2017-09-01

    With high contrast and deep penetration, two-photon fluorescence (2PF) imaging has become one of the most promising in vivo fluorescence imaging techniques. To obtain good imaging contrast, fluorescent nanoprobes with good 2PF properties are highly needed. In this work, bright 2PF polymer dots (P dots) were applied for in vivo mouse brain imaging. Deep-red emissive P dots with PFBT as the donor and PFDBT5 as the acceptor were synthesized and used as a contrast agent. P dots were further encapsulated by poly(styrene-co-maleic anhydride) (PSMA) and grafted with poly(ethylene glycol) (PEG). The P dots-PEG exhibit large two-photon absorption (2PA) cross-sections (δ≥8500 g), good water dispersibility, and high biocompatibility. P dots-PEG was further utilized first time for in vivo vascular imaging of mouse ear and brain, under 690-900 nm femtosecond (fs) laser excitation. Due to the large 2PA cross-section and deep-red emission, a large imaging depth ( 720 μm) was achieved.

  14. Brain MR imaging in children with psychomotor developmental delay

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, Toshinori; Korogi, Yukunori; Sakamoto, Yuji; Furusawa, Mitsuhiro; Hamatake, Satoshi; Takahashi, Mutsumasa (Kumamoto Univ. (Japan). School of Medicine)

    1994-06-01

    Fifty-two patients with developmental delay of unknown cause underwent MR imaging of the brain. Their ages ranged from 5 months to 22 years, with a mean of 2.2 years. Thirty-seven (71%) had positive MR findings, including nine with congenital malformation, nine with atrophy, six with white matter lesion, five with delayed myelination, five with atrophy and delayed myelination, two with acquired injury of corpus callosum, and one with ulegyria. Congenital malformations obtained included holoprosencephaly, polymicrogyria, dysgenesis of corpus callosum, hypoplasia of cerebellum, and tuberous sclerosis. Abnormal MR findings were frequently observed both in the children with neurologic physical findings and in generally retarded children, while in the children with suspected autism, MR imaging did not demonstrate any abnormalities. Of 24 patients with epilepsy, abnormal MR findings were obtained in 17 patients (71%). The frequency of white matter lesion and atrophy was slightly higher in the patients with epilepsy. However, no significant correlations were found between MR findings and the presence of epilepsy. Also, no significant correlations were obtained between MR findings and the degree of developmental quotient (DQ). Severely injured cases did not necessarily show abnormal findings on MRI. (author).

  15. Imaging liver and brain glycogen metabolism at the nanometer scale.

    Science.gov (United States)

    Takado, Yuhei; Knott, Graham; Humbel, Bruno M; Escrig, Stéphane; Masoodi, Mojgan; Meibom, Anders; Comment, Arnaud

    2015-01-01

    In mammals, glycogen synthesis and degradation are dynamic processes regulating blood and cerebral glucose-levels within a well-defined physiological range. Despite the essential role of glycogen in hepatic and cerebral metabolism, its spatiotemporal distribution at the molecular and cellular level is unclear. By correlating electron microscopy and ultra-high resolution ion microprobe (NanoSIMS) imaging of tissue from fasted mice injected with (13)C-labeled glucose, we demonstrate that liver glycogenesis initiates in the hepatocyte perinuclear region before spreading toward the cell membrane. In the mouse brain, we observe that (13)C is inhomogeneously incorporated into astrocytic glycogen at a rate ~25 times slower than in the liver, in agreement with prior bulk studies. This experiment, using temporally resolved, nanometer-scale imaging of glycogen synthesis and degradation, provides greater insight into glucose metabolism in mammalian organs and shows how this technique can be used to explore biochemical pathways in healthy and diseased states. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. The addicted brain: imaging neurological complications of recreational drug abuse.

    Science.gov (United States)

    Montoya-Filardi, A; Mazón, M

    Recreational drug abuse represents a serious public health problem. Neuroimaging traditionally played a secondary role in this scenario, where it was limited to detecting acute vascular events. However, thanks to advances in knowledge about disease and in morphological and functional imaging techniques, radiologists have now become very important in the diagnosis of acute and chronic neurological complications of recreational drug abuse. The main complications are neurovascular disease, infection, toxicometabolic disorders, and brain atrophy. The nonspecific symptoms and denial of abuse make the radiologist's involvement fundamental in the management of these patients. Neuroimaging makes it possible to detect early changes and to suggest an etiological diagnosis in cases with specific patterns of involvement. We aim to describe the pattern of abuse and the pathophysiological mechanisms of the drugs with the greatest neurological repercussions as well as to illustrate the depiction of the acute and chronic cerebral complications on conventional and functional imaging techniques. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Comparison of synthetic HDL contrast agents for MR imaging of atherosclerosis

    Science.gov (United States)

    Cormode, David P.; Chandrasekar, Rohith; Delshad, Amanda; Briley-Saebo, Karen C.; Calcagno, Claudia; Barazza, Alessandra; Mulder, Willem J. M.

    2009-01-01

    Determining arterial macrophage expression is an important goal in the molecular imaging of atherosclerosis. Here we compare the efficacy of two synthetic, HDL-based contrast agents for magnetic resonance imaging (MRI) of macrophage burden. Each form of HDL was labeled with gadolinium and rhodamine to allow MRI and fluorescence microscopy. Either the 37 or 18 amino acid peptide replaced the apolipoprotein A-I in these agents, which were termed 37pA-Gd or 18A-Gd. The diameters of 37pA-Gd and 18A-Gd are 7.6 nm and 8.0 nm, respectively, while the longitudinal relaxivities are 9.8 and 10.0 (mMs)-1. 37pA has better lipid binding properties. In vitro tests with J774A.1 macrophages proved the particles possessed the functionality of HDL by eliciting cholesterol efflux and were taken up in a receptor-like fashion by the cells. Both agents produced enhancements in atherosclerotic plaques of apolipoprotein E knockout mice of ~90% (n=7 per agent) and are macrophage specific as evidenced by confocal microscopy on aortic sections. The half-lives of 37pA-Gd and 18A-Gd are 2.6 and 2.1 hours, respectively. Despite the more favorable lipid interactions of 37pA, both agents gave similar, excellent contrast for the detection of atherosclerotic macrophages using MRI. PMID:19378935

  18. Comparison of synthetic high density lipoprotein (HDL) contrast agents for MR imaging of atherosclerosis.

    Science.gov (United States)

    Cormode, David P; Chandrasekar, Rohith; Delshad, Amanda; Briley-Saebo, Karen C; Calcagno, Claudia; Barazza, Alessandra; Mulder, Willem J M; Fisher, Edward A; Fayad, Zahi A

    2009-05-20

    Determining arterial macrophage expression is an important goal in the molecular imaging of atherosclerosis. Here, we compare the efficacy of two synthetic, high density lipoprotein (HDL) based contrast agents for magnetic resonance imaging (MRI) of macrophage burden. Each form of HDL was labeled with gadolinium and rhodamine to allow MRI and fluorescence microscopy. Either the 37 or 18 amino acid peptide replaced the apolipoprotein A-I in these agents, which were termed 37pA-Gd or 18A-Gd. The diameters of 37pA-Gd and 18A-Gd are 7.6 and 8.0 nm, respectively, while the longitudinal relaxivities are 9.8 and 10.0 (mM s)(-1). 37pA has better lipid binding properties. In vitro tests with J774A.1 macrophages proved the particles possessed the functionality of HDL by eliciting cholesterol efflux and were taken up in a receptor-like fashion by the cells. Both agents produced enhancements in atherosclerotic plaques of apolipoprotein E knockout mice of approximately 90% (n = 7 per agent) and are macrophage specific as evidenced by confocal microscopy on aortic sections. The half-lives of 37pA-Gd and 18A-Gd are 2.6 and 2.1 h, respectively. Despite the more favorable lipid interactions of 37pA, both agents gave similar, excellent contrast for the detection of atherosclerotic macrophages using MRI.

  19. Brain Basics

    Medline Plus

    Full Text Available ... Life Brain Basics in Real Life—How Depression affects the Brain Meet Sarah Sarah is a middle- ... than ever before. Brain Imaging Using brain imaging technologies such as magnetic resonance imaging (MRI), which uses ...

  20. Galactosylated iodine-based small molecule I.V. CT contrast agent for bile duct imaging.

    Science.gov (United States)

    Jung, Yeonjin; Hwang, Hee Sook; Na, Kun

    2018-04-01

    Computed tomography (CT) with contrast plays an important role as a clinical diagnostic tool but still has a limited diagnostic range. In this work, we developed a novel injectable iodine-based small molecule CT contrast agent, even can be used for bile duct diagnostics. The bile duct diagnosable CT contrast agent (BDICA) is synthesized with 5-amino-2,4,6-triiodoisophthaloyl dichloride (ATIPC), tromethamine and lactobionic acid (LBA) for asialoglycoprotein receptor (ASGPR) targeted delivery via receptor-mediated endocytosis and transport to the bile canaliculi. Specific binding to the ASGPRs was confirmed by in vitro cellular uptake in HepG2 cells (ASGPR positive) and HCT 116 cells (ASGPR negative). Compared to iohexol, BDICA has equal in vivo distribution and a 13-fold iodine increase in content was observed in bile juice after BDICA injection. The radiopaque contrast effect in the bile duct has been clearly shown in in vivo CT scans. Furthermore, within 36 h, 91.3% of the BDICA was eliminated without organ damage, which verified the overall safety of the contrast agent. BDICA not only provides sufficient contrast images similar to iohexol, but also provides superior images of the bile duct. Based on recent studies, it has been shown that BDICA is a promising, safe and effective contrast agent for CT imaging of the organs and soft tissues, including the bile duct. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. SPECT brain imaging in epilepsy: a meta-analysis.

    Science.gov (United States)

    Devous, M D; Thisted, R A; Morgan, G F; Leroy, R F; Rowe, C C

    1998-02-01

    A meta-analysis of SPECT brain imaging in epilepsy was performed to derive the sensitivity and specificity of interictal, postictal or ictal rCBF patterns to identify a seizure focus in medically refractory patients. Papers were obtained by pooling all published articles identified by two independent literature searches: (a) Dialnet (EMBASE) or Radline by CD-ROM and (b) Current Contents searched manually. Literature inclusion criteria were: (a) patients had a localization-related epileptic syndrome; (b) more than six patients were reported; and (c) patients had at least an interictal EEG-documented epileptiform abnormality. Of 46 papers meeting these criteria, 30 contained extractable data. SPECT results were compared to localization by standard diagnostic evaluation and surgical outcome. Meta-analytic sensitivities for SPECT localization in patients with temporal lobe seizures relative to diagnostic evaluation were 0.44 (interictal), 0.75 (postictal) and 0.97 (ictal). Similar results were obtained relative to surgical outcome. False-positive rates were low relative to diagnostic evaluation (7.4% for interictal and 1.5% for postictal studies) and surgical outcome (4.4% for interictal and 0.0% for postictal studies). The results were not dependent on tracer used (or dose), the presence of CT-identified structural abnormalities, blinding of image interpretation or camera quality (although data were more variable with low-resolution cameras). There were insufficient data for conclusions regarding extratemporal-seizure or pediatric epilepsy populations. Insights gained from reviewing this literature yielded recommendations for minimal information that should be provided in future reports. Additional recommendations regarding the nature and focus of future studies also are provided. The most important of these is that institutions using SPECT imaging in epilepsy should perform ictal, preferably, or postictal scanning in combination with interictal scanning.

  2. Performance Assessment for Brain MR Imaging Registration Methods.

    Science.gov (United States)

    Lin, J S; Fuentes, D T; Chandler, A; Prabhu, S S; Weinberg, J S; Baladandayuthapani, V; Hazle, J D; Schellingerhout, D

    2017-05-01

    Clinical brain MR imaging registration algorithms are often made available by commercial vendors without figures of merit. The purpose of this study was to suggest a rational performance comparison methodology for these products. Twenty patients were imaged on clinical 3T scanners by using 4 sequences: T2-weighted, FLAIR, susceptibility-weighted angiography, and T1 postcontrast. Fiducial landmark sites (n = 1175) were specified throughout these image volumes to define identical anatomic locations across sequences. Multiple registration algorithms were applied by using the T2 sequence as a fixed reference. Euclidean error was calculated before and after each registration and compared with a criterion standard landmark registration. The Euclidean effectiveness ratio is the fraction of Euclidean error remaining after registration, and the statistical effectiveness ratio is similar, but accounts for dispersion and noise. Before registration, error values for FLAIR, susceptibility-weighted angiography, and T1 postcontrast were 2.07 ± 0.55 mm, 2.63 ± 0.62 mm, and 3.65 ± 2.00 mm, respectively. Postregistration, the best error values for FLAIR, susceptibility-weighted angiography, and T1 postcontrast were 1.55 ± 0.46 mm, 1.34 ± 0.23 mm, and 1.06 ± 0.16 mm, with Euclidean effectiveness ratio values of 0.493, 0.181, and 0.096 and statistical effectiveness ratio values of 0.573, 0.352, and 0.929 for rigid mutual information, affine mutual information, and a commercial GE registration, respectively. We demonstrate a method for comparing the performance of registration algorithms and suggest the Euclidean error, Euclidean effectiveness ratio, and statistical effectiveness ratio as performance metrics for clinical registration algorithms. These figures of merit allow registration algorithms to be rationally compared. © 2017 by American Journal of Neuroradiology.

  3. Blood-brain barrier molecular trojan horse enables imaging of brain uptake of radioiodinated recombinant protein in the rhesus monkey.

    Science.gov (United States)

    Boado, Ruben J; Hui, Eric K-W; Lu, Jeff Zhiqiang; Sumbria, Rachita K; Pardridge, William M

    2013-10-16

    Recombinant proteins are large molecule drugs that do not cross the blood-brain barrier (BBB). However, BBB-penetration of protein therapeutics is enabled by re-engineering the recombinant protein as IgG fusion proteins. The IgG domain is a monoclonal antibody (mAb) against an endogenous BBB receptor-mediated transport system, such as the human insulin receptor (HIR), and acts as a molecular Trojan horse to ferry the fused protein across the BBB. In the present study, a recombinant lysosomal enzyme, iduronate 2-sulfatase (IDS), is fused to the HIRMAb, and BBB penetration of the IDS alone vs the HIRMAb-IDS fusion protein is compared in the Rhesus monkey. Recombinant IDS and the HIRMAb-IDS fusion protein were radiolabeled with indirect iodination with the [(125)I]-Bolton-Hunter reagent and with direct iodination with Iodogen/[(125)I]-idodine. IDS and the HIRMAb-IDS fusion protein have comparable plasma pharmacokinetics and uptake by peripheral organs. IDS does not cross the BBB. The HIRMAb-IDS fusion protein crosses the BBB and the brain uptake is 1% of injected dose/brain. Brain imaging shows HIRMAb-IDS penetration to all parts of brain, and immunoprecipitation of brain radioactivity shows intact fusion protein in brain. The use of BBB molecular Trojan horses enables brain imaging of recombinant proteins that are re-engineered for BBB transport.

  4. Medical applications of nanoparticles in biological imaging, cell labeling, antimicrobial agents, and anticancer nanodrugs.

    Science.gov (United States)

    Singh, Ravina; Nalwa, Hari Singh

    2011-08-01

    This article reviews the applications of nanotechnology in the fields of medical and life sciences. Nanoparticles have shown promising applications from diagnosis to treatment of various types of diseases including cancer. In this review, we discuss the applications of nanostructured materials such as nanoparticles, quantum dots, nanorods, nanowires, and carbon nanotubes in diagnostics, biomarkers, cell labeling, contrast agents for biological imaging, antimicrobial agents, drug delivery systems, and anticancer nanodrugs for treatment of cancer and other infectious diseases. The adverse affects of nanoparticles on human skin from daily use in cosmetics and general toxicology of nanoscale materials are also reviewed.

  5. Magnetic Resonance Imaging to Assess Blood–Brain Barrier Damage in Murine Trypanosomiasis

    Science.gov (United States)

    Rodgers, Jean; McCabe, Christopher; Gettinby, George; Bradley, Barbara; Condon, Barrie; Kennedy, Peter G. E.

    2011-01-01

    The ability of trypanosomes to invade the brain and induce an inflammatory reaction is well-recognized. This study uses magnetic resonance imaging (MRI) in conjunction with a murine model of central nervous system (CNS) stage trypanosomiasis to investigate this phenomenon at the level of the blood–brain barrier (BBB). Mice were scanned before and after administration of the contrast agent. Signal enhancement maps were generated, and the percentage signal change was calculated. The severity of the neuroinflammation was also assessed. Statistical analysis of the signal change data revealed a significantly (P = 0.028) higher signal enhancement in mice at 28 days post-infection (least squares mean = 26.709) compared with uninfected animals (6.298), indicating the presence of BBB impairment. Leukocytes were found in the meninges and perivascular space of some blood vessels in the infected mice. This study shows that the integrity of the BBB is compromised during CNS stage trypanosomiasis and that the impairment does not correlate with inflammatory cell infiltration. PMID:21292912

  6. Uptake of perfusion imaging agents by transplanted hearts: an experimental study in rats

    Energy Technology Data Exchange (ETDEWEB)

    Bergsland, J.; Carr, E.A. Jr.; Carroll, M.; Feldman, M.J.; Kung, H.; Wright, J.R.

    1989-02-01

    There is a need for a reliable noninvasive marker of rejection in transplanted hearts. Endomyocardial biopsy is now the universally accepted diagnostic method of choice, but the invasiveness of the procedure and the limited size of the sample obtained makes this method far from ideal. As coronary blood flow may be expected to decrease during acute rejection, there has been interest in thallium-201 chloride (T1), a perfusion marker, as an imaging agent for diagnosing cardiac rejection. Hexakis(t-butylisonitrile)-technetium (Tc-TBI) is a representative of a new class of radiopharmaceuticals proposed as perfusion markers. We have compared the uptake of these imaging agents in a rat model of cardiac transplantation. Uptake of Tc-TBI as well as of T1 was significantly lower in rejecting than in nonrejecting hearts. This change was found in both left (LV) and right (RV) ventricles. Allografts in animals treated with cyclosporine (CyA) showed less severe rejection and higher uptakes of both imaging agents as compared to unmodified rejection. Our results suggest that perfusion imaging with these radionuclides is a potentially useful approach to the problem of detecting allograft rejection.

  7. Three-dimensional, isotropic imaging of mouse brain using multi-view deconvolution light sheet microscopy

    Directory of Open Access Journals (Sweden)

    Sa Liu

    2017-09-01

    Full Text Available We present a three-dimensional (3D isotropic imaging of mouse brain using light-sheet fluorescent microscopy (LSFM in conjunction with a multi-view imaging computation. Unlike common single view LSFM is used for mouse brain imaging, the brain tissue is 3D imaged under eight views in our study, by a home-built selective plane illumination microscopy (SPIM. An output image containing complete structural information as well as significantly improved resolution (∼4 times are then computed based on these eight views of data, using a bead-guided multi-view registration and deconvolution. With superior imaging quality, the astrocyte and pyramidal neurons together with their subcellular nerve fibers can be clearly visualized and segmented. With further including other computational methods, this study can be potentially scaled up to map the connectome of whole mouse brain with a simple light-sheet microscope.

  8. Deep-brain imaging via epi-fluorescence Computational Cannula Microscopy

    Science.gov (United States)

    Kim, Ganghun; Nagarajan, Naveen; Pastuzyn, Elissa; Jenks, Kyle; Capecchi, Mario; Shepherd, Jason; Menon, Rajesh

    2017-03-01

    Here we demonstrate widefield (field diameter = 200 μm) fluorescence microscopy and video imaging inside the rodent brain at a depth of 2 mm using a simple surgical glass needle (cannula) of diameter 0.22 mm as the primary optical element. The cannula guides excitation light into the brain and the fluorescence signal out of the brain. Concomitant image-processing algorithms are utilized to convert the spatially scrambled images into fluorescent images and video. The small size of the cannula enables minimally invasive imaging, while the long length (>2 mm) allow for deep-brain imaging with no additional complexity in the optical system. Since no scanning is involved, widefield fluorescence video at the native frame rate of the camera can be achieved.

  9. Experimental design and instability analysis of coaxial electrospray process for microencapsulation of drugs and imaging agents.

    Science.gov (United States)

    Si, Ting; Zhang, Leilei; Li, Guangbin; Roberts, Cynthia J; Yin, Xiezhen; Xu, Ronald

    2013-07-01

    Recent developments in multimodal imaging and image-guided therapy requires multilayered microparticles that encapsulate several imaging and therapeutic agents in the same carrier. However, commonly used microencapsulation processes have multiple limitations such as low encapsulation efficiency and loss of bioactivity for the encapsulated biological cargos. To overcome these limitations, we have carried out both experimental and theoretical studies on coaxial electrospray of multilayered microparticles. On the experimental side, an improved coaxial electrospray setup has been developed. A customized coaxial needle assembly combined with two ring electrodes has been used to enhance the stability of the cone and widen the process parameter range of the stable cone-jet mode. With this assembly, we have obtained poly(lactide-co-glycolide) microparticles with fine morphology and uniform size distribution. On the theoretical side, an instability analysis of the coaxial electrified jet has been performed based on the experimental parameters. The effects of process parameters on the formation of different unstable modes have been studied. The reported experimental and theoretical research represents a significant step toward quantitative control and optimization of the coaxial electrospray process for microencapsulation of multiple drugs and imaging agents in multimodal imaging and image-guided therapy.

  10. Neuroimaging Feature Terminology: A Controlled Terminology for the Annotation of Brain Imaging Features.

    Science.gov (United States)

    Iyappan, Anandhi; Younesi, Erfan; Redolfi, Alberto; Vrooman, Henri; Khanna, Shashank; Frisoni, Giovanni B; Hofmann-Apitius, Martin

    2017-01-01

    Ontologies and terminologies are used for interoperability of knowledge and data in a standard manner among interdisciplinary research groups. Existing imaging ontologies capture general aspects of the imaging domain as a whole such as methodological concepts or calibrations of imaging instruments. However, none of the existing ontologies covers the diagnostic features measured by imaging technologies in the context of neurodegenerative diseases. Therefore, the Neuro-Imaging Feature Terminology (NIFT) was developed to organize the knowledge domain of measured brain features in association with neurodegenerative diseases by imaging technologies. The purpose is to identify quantitative imaging biomarkers that can be extracted from multi-modal brain imaging data. This terminology attempts to cover measured features and parameters in brain scans relevant to disease progression. In this paper, we demonstrate the systematic retrieval of measured indices from literature and how the extracted knowledge can be further used for disease modeling that integrates neuroimaging features with molecular processes.

  11. Perfusion magnetic resonance imaging in pediatric brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Dallery, F.; Michel, D.; Constans, J.M.; Gondry-Jouet, C. [University Hospital, Department of Radiology, Amiens (France); Bouzerar, R.; Promelle, V.; Baledent, O. [University Hospital, Department of Imaging and Biophysics, Amiens (France); Attencourt, C. [University Hospital, Departement of Pathology, Amiens (France); Peltier, J. [University Hospital, Departement of Neurosurgery, Amiens (France)

    2017-11-15

    The use of DSC-MR imaging in pediatric neuroradiology is gradually growing. However, the number of studies listed in the literature remains limited. We propose to assess the perfusion and permeability parameters in pediatric brain tumor grading. Thirty children with a brain tumor having benefited from a DSC-MR perfusion sequence have been retrospectively explored. Relative CBF and CBV were computed on the ROI with the largest lesion coverage. Assessment of the lesion's permeability was also performed through the semi-quantitative PSR parameter and the K2 model-based parameter on the whole-lesion ROI and a reduced ROI drawn on the permeability maps. A statistical comparison of high- and low-grade groups (HG, LG) as well as a ROC analysis was performed on the histogram-based parameters. Our results showed a statistically significant difference between LG and HG groups for mean rCBV (p < 10{sup -3}), rCBF (p < 10{sup -3}), and for PSR (p = 0.03) but not for the K2 factor (p = 0.5). However, the ratio K2/PSR was shown to be a strong discriminating factor between the two groups of lesions (p < 10{sup -3}). For rCBV and rCBF indicators, high values of ROC AUC were obtained (> 0.9) and mean value thresholds were observed at 1.07 and 1.03, respectively. For K2/PSR in the reduced area, AUC was also superior to 0.9. The implementation of a dynamic T2* perfusion sequence provided reliable results using an objective whole-lesion ROI. Perfusion parameters as well as a new permeability indicator could efficiently discriminate high-grade from low-grade lesions in the pediatric population. (orig.)

  12. Utility of susceptibility-weighted imaging and arterial spin perfusion imaging in pediatric brain arteriovenous shunting

    Energy Technology Data Exchange (ETDEWEB)

    Nabavizadeh, Seyed Ali; Edgar, J.C.; Vossough, Arastoo [University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2014-10-15

    The objectives of the study are to investigate the application of susceptibility-weighted imaging (SWI) and arterial spin labeling (ASL) imaging in the assessment of shunting and the draining veins in pediatric patients with arteriovenous shunting and compare the utility of SWI and ASL with conventional MR and digital subtraction angiography (DSA). This study is a retrospective study of 19 pediatric patients with arteriovenous shunting on brain MRI who were also evaluated with DSA. We assessed the ability of conventional MRI sequences, susceptibility magnitude images, phase-filtered SWI images, and pulsed ASL images in the detection of arteriovenous (AV) shunting, number of draining veins and drainage pathways in comparison to DSA. The mean number of detected draining veins on DSA (3.63) was significantly higher compared to SWI phase-filtered image (mean = 2.72), susceptibility magnitude image (mean = 2.92), ASL (mean = 1.76) and conventional MRI (2.47) (p < 0.05). Pairwise comparison of DSA difference scores (i.e., difference between MR modalities in the number of missed draining veins) revealed no difference between the MR modalities (p > 0.05). ASL was the only method that correctly identified superficial and deep venous drainage in all patients. Regarding detection of shunting, ASL, SWI phase-filtered, and magnitude images demonstrated shunting in 100, 83, and 84 % of patients, respectively. SWI depicts a higher number of draining vein compared to conventional MR pulse sequences. ASL is a sensitive approach in showing 100 % sensitivity in the detection of AV shunting and in the diagnosis of the pattern of venous drainage. The present findings suggest the added utility of both SWI and ASL in the assessment of AV shunting. (orig.)

  13. Novel Tc-99m radiotracers for brain imaging

    Directory of Open Access Journals (Sweden)

    Alessandra Boschi

    2007-09-01

    Full Text Available A novel class of Tc-99m complexes able to cross the blood brain barrier has been investigated and described here. These compounds are formed by reacting the bis-substituted nitrido precusors [99mTc(N(PS2] (PS = phosphino-thiol ligand with triethylborane (BEt3 under strictly anhydrous conditions and using non-aqueous solvents. The molecular structure of these tracers was not fully established, but preliminary experimental evidence suggests that they result from the interaction of the Lewis base [99mTc(N(PS2] with the Lewis acid BEt3, which leads to the formation of the novel -B-Nº Tc- adduct. After purification and recovery in a physiological solution, the new borane-nitrido Tc-99m derivatives were injected in rats for evaluating their in vivo biological behavior. Results showed a significant accumulation in brain tissue, thus indicating that these complexes are capable of penetrating the intact blood brain barrier. Uptake in the central nervous system was confirmed by imaging the distribution of activity on the integrated living animal using a YAP(SSPECT small animal scanner.Uma nova classe de complexos de Tc-99m capazes de atravessar a barreira hemato-encefálica foi investigada e descrita neste trabalho. Estes compostos são formados reagindo os precursores bissubstituídos do nitrido [99mTc(N(PS2] (PS = phosphino-tiol ligante com trietillborano (BEt3 sob restritas condições anidras e usando solventes não aquosos. A estrutura molecular desses traçadores não foi totalmente estabelecida, mas evidências experimentais preliminares sugerem que eles resultam da interação da base de Lewis [99mTc(N(PS2] com o ácido de Lewis BEt3, levando a formação do novo aducto -B-Nº Tc-. Após purificação e recuperação em uma solução fisiológica, os novos derivados borano-nitrido-Tc-99m foram injetados em ratos para avaliação de seu comportamento biológico in vivo. Os resultados mostraram uma acumulação significativa no tecido cerebral

  14. Ribbon scanning confocal for high-speed high-resolution volume imaging of brain.

    Directory of Open Access Journals (Sweden)

    Alan M Watson

    Full Text Available Whole-brain imaging is becoming a fundamental means of experimental insight; however, achieving subcellular resolution imagery in a reasonable time window has not been possible. We describe the first application of multicolor ribbon scanning confocal methods to collect high-resolution volume images of chemically cleared brains. We demonstrate that ribbon scanning collects images over ten times faster than conventional high speed confocal systems but with equivalent spectral and spatial resolution. Further, using this technology, we reconstruct large volumes of mouse brain infected with encephalitic alphaviruses and demonstrate that regions of the brain with abundant viral replication were inaccessible to vascular perfusion. This reveals that the destruction or collapse of large regions of brain micro vasculature may contribute to the severe disease caused by Venezuelan equine encephalitis virus. Visualization of this fundamental impact of infection would not be possible without sampling at subcellular resolution within large brain volumes.

  15. Label-free, multi-scale imaging of ex-vivo mouse brain using spatial light interference microscopy

    Science.gov (United States)

    Min, Eunjung; Kandel, Mikhail E.; Ko, Chemyong J.; Popescu, Gabriel; Jung, Woonggyu; Best-Popescu, Catherine

    2016-12-01

    Brain connectivity spans over broad spatial scales, from nanometers to centimeters. In order to understand the brain at multi-scale, the neural network in wide-field has been visualized in detail by taking advantage of light microscopy. However, the process of staining or addition of fluorescent tags is commonly required, and the image contrast is insufficient for delineation of cytoarchitecture. To overcome this barrier, we use spatial light interference microscopy to investigate brain structure with high-resolution, sub-nanometer pathlength sensitivity without the use of exogenous contrast agents. Combining wide-field imaging and a mosaic algorithm developed in-house, we show the detailed architecture of cells and myelin, within coronal olfactory bulb and cortical sections, and from sagittal sections of the hippocampus and cerebellum. Our technique is well suited to identify laminar characteristics of fiber tract orientation within white matter, e.g. the corpus callosum. To further improve the macro-scale contrast of anatomical structures, and to better differentiate axons and dendrites from cell bodies, we mapped the tissue in terms of its scattering property. Based on our results, we anticipate that spatial light interference microscopy can potentially provide multiscale and multicontrast perspectives of gross and microscopic brain anatomy.

  16. Cluster imaging of multi-brain networks (CIMBN: a general framework for hyperscanning and modeling a group of interacting brains

    Directory of Open Access Journals (Sweden)

    Lian eDuan

    2015-07-01

    Full Text Available Studying the neural basis of human social interactions is a key topic in the field of social neuroscience. Brain imaging studies in this field usually focus on the neural correlates of the social interactions between two participants. However, as the participant number further increases, even by a small amount, great difficulties raise. One challenge is how to concurrently scan all the interacting brains with high ecological validity, especially for a large number of participants. The other challenge is how to effectively model the complex group interaction behaviors emerging from the intricate neural information exchange among a group of socially organized people. Confronting these challenges, we propose a new approach called Cluster Imaging of Multi-brain Networks (CIMBN. CIMBN consists of two parts. The first part is a cluster imaging technique with high ecological validity based on multiple functional near-infrared spectroscopy (fNIRS systems. Using this technique, we can easily extend the simultaneous imaging capacity of social neuroscience studies up to dozens of participants. The second part of CIMBN is a multi-brain network (MBN modeling method based on graph theory. By taking each brain as a network node and the relationship between any two brains as a network edge, one can construct a network model for a group of interacting brains. The emergent group social behaviors can then be studied using the network’s properties, such as its topological structure and information exchange efficiency. Although there is still much work to do, as a general framework for hyperscanning and modeling a group of interacting brains, CIMBN can provide new insights into the neural correlates of group social interactions, and advance social neuroscience and social psychology.

  17. FTIR, Raman, and CARS microscopic imaging for histopathologic assessment of brain tumors

    Science.gov (United States)

    Krafft, Christoph; Bergner, Norbert; Matthäus, Christian; Romeike, Bernd; Reichart, Rupert; Kalff, Rolf; Dietzek, B.,; Popp, Jürgen

    2010-02-01

    The contribution demonstrates how the molecular contrast of Fourier transform infrared (FTIR), Raman and coherent anti-Stokes Raman scattering (CARS) microscopic imaging can be applied for the histopathological assessment of brain tumors. Human brain tissue specimens were obtained from patients undergoing neurosurgery. Thin sections of control brain tissue from an epilepsy patient and tumor tissue from a meningioma patient were prepared on calciumfluoride slides which were appropriate substrates for data acquisition in transmission and reflection mode. All CARS images correlate well with the FTIR and Raman images. Whereas CARS images were collected within seconds, exposure times were minutes for FTIR imaging and hours for Raman imaging. CARS images in the interval 2750-3000 cm-1 mainly probed spectral contributions of lipids which are important diagnostic markers of brain tumors. It was demonstrated that the CARS profile in the interval 2750-3000 cm-1 differed between the control sample and meningioma. Full spectral information could be extracted from Raman and FTIR images that enabled to distinguish different tissue types in brain tumors. Based on the current results we suggest a complementary application of FTIR, Raman and CARS imaging. FTIR and Raman imaging defines spectral regions and spectral markers that are essential for tissue classification. CARS images at different Stokes shifts or in the multiplex mode probe these spectral descriptors at video-time frame rates.

  18. Design and construction of a brain phantom to simulate neonatal MR images.

    Science.gov (United States)

    Kazemi, Kamran; Moghaddam, Hamid Abrishami; Grebe, Reinhard; Gondry-Jouet, Catherine; Wallois, Fabrice

    2011-04-01

    This paper presents the design and construction of a 3D digital neonatal neurocranial phantom and its application for the simulation of brain magnetic resonance (MR) images. Commonly used digital brain phantoms (e.g. BrainWeb) are based on the adult brain. With the growing interest in computer-aided methods for neonatal MR image processing, there is a growing demand a digital phantom and brain MR image simulator especially for the neonatal brains. This is due to the pronounced differences between adult and neonatal brains not only in terms of size but also, more importantly, in terms of geometrical proportions and the need to subdivide white matter into two different tissue types in neonates. Therefore the neonatal brain phantom created in the here presented work consists of 9 different tissue types: skin, fat, muscle, skull, dura mater, gray matter, myelinated white matter, nonmyelinated white matter and cerebrospinal fluid. Each voxel has a vector consisting of 9 components, one for each of these nine tissue types. This digital phantom can be used to map simulated magnetic resonance signal intensities resulting in simulated MR images of the newborns head. These images with controlled degradation of the image data present a representative, reproducible data set ideal for development and evaluation of neonatal MRI analysis methods, e.g. segmentation and registration algorithms. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. A generic framework for modeling brain deformation as a constrained parametric optimization problem to aid non-diffeomorphic image registration in brain tumor imaging.

    Science.gov (United States)

    Mang, A; Toma, A; Schuetz, T A; Becker, S; Buzug, T M

    2012-01-01

    In the present paper a novel computational framework for modeling tumor induced brain deformation as a biophysical prior for non-rigid image registration is described. More precisely, we aim at providing a generic building block for non-rigid image registration that can be used to resolve inherent irregularities in non-diffeomorphic registration problems that naturally arise in serial and cross-population brain tumor imaging studies due to the presence (or progression) of pathology. The model for the description of brain cancer dynamics on a tissue level is based on an initial boundary value problem (IBVP). The IBVP follows the accepted assumption that the progression of primary brain tumors on a tissue level is governed by proliferation and migration of cancerous cells into surrounding healthy tissue. The model of tumor induced brain deformation is phrased as a parametric, constrained optimization problem. As a basis of comparison and to demonstrate generalizability additional soft constraints (penalties) are considered. A back-tracking line search is implemented in conjunction with a limited memory Broyden-Fletcher-Goldfarb-Shanno (LBFGS) method in order to handle the numerically delicate log-barrier strategy for confining volume change. Numerical experiments are performed to test the flexible control of the computed deformation patterns in terms of varying model parameters. The results are qualitatively and quantitatively related to patterns in patient individual magnetic resonance imaging data. Numerical experiments demonstrate the flexible control of the computed deformation patterns. This in turn strongly suggests that the model can be adapted to patient individual imaging patterns of brain tumors. Qualitative and quantitative comparison of the computed cancer profiles to patterns in medical imaging data of an exemplary patient demonstrates plausibility. The designed optimization problem is based on computational tools widely used in non-rigid image

  20. Imaging plasma docosahexaenoic acid (dha incorporation into the brain in vivo, as a biomarker of brain DHA: Metabolism and neurotransmission

    Directory of Open Access Journals (Sweden)

    Rapoport Stanley I.

    2011-09-01

    Full Text Available Docosahexaenoic acid (DHA is critical for normal brain structure and function, and its brain concentration depends on dietary DHA content and hepatic conversion from its dietary derived n-3 precursor, a-linolenic acid (α-LNA. We developed an in vivo method in rats using quantitative autoradiography to image incorporation into brain of unesterified plasma DHA, and showed that the incorporation rate equals the rate of brain metabolic DHA consumption. Thus, quantitative imaging of DHA incorporation from plasma into brain can be used as a biomarker of brain DHA metabolism and neurotransmission. The method has been extended to humans with the use of positron emission tomography (PET. Furthermore, imaging in unanesthetized rats using DHA incorporation as a biomarker in response to N-methyl-D-aspartate (NMDA administration confirms that regional DHA signaling is independent of extracellular calcium, and likely mediated by a calcium-independent phospholipase A2 (iPLA2. Studies in mice in which iPLA2-VIA (β was knocked out confirmed that this enzyme is critical for baseline and muscarinic cholinergic signaling involving DHA.

  1. Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast agent dose: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Peijie; Liu, Jie; Chai, Yaru; Yan, Xiaopeng; Gao, Jianbo; Dong, Junqiang [The First Affiliated Hospital of Zhengzhou University, Department of Radiology, Zhengzhou, Henan Province (China)

    2017-01-15

    To evaluate the feasibility, image quality, and radiation dose of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) with reduced contrast agent dose in abdominal multiphase CT. One hundred and sixty patients were randomly divided into two scan protocols (n = 80) each; protocol A, 120 kVp/450 mgI/kg, filtered back projection algorithm (FBP); protocol B, spectral CT imaging with ASIS and 40 to 70 keV monochromatic images generated per 300 mgI/kg, ASIR algorithm. Quantitative parameters (image noise and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (image noise, small structures, organ enhancement, and overall image quality) were compared. Monochromatic images at 50 keV and 60 keV provided similar or lower image noise, but higher contrast and overall image quality as compared with 120-kVp images. Despite the higher image noise, 40-keV images showed similar overall image quality compared to 120-kVp images. Radiation dose did not differ between the two protocols, while contrast agent dose in protocol B was reduced by 33 %. Application of ASIR and ASIS to monochromatic imaging from 40 to 60 keV allowed contrast agent dose reduction with adequate image quality and without increasing radiation dose compared to 120 kVp with FBP. (orig.)

  2. Synthesis of cytocompatible Fe3O4@ZSM-5 nanocomposite as magnetic resonance imaging contrast agent

    Science.gov (United States)

    Atashi, Zahra; Divband, Baharak; Keshtkar, Ahmad; Khatamian, Maasoumeh; Farahmand-Zahed, Farzane; Nazarlo, Ali Kiani; Gharehaghaji, Nahideh

    2017-09-01

    In this study, ZSM-5 nano zeolite was used as a support material for iron oxide nanoparticles and the potential ability of the nanocomposite for magnetic resonance imaging (MRI) contrast agent was investigated. The nanocomposite was synthesized by hydrothermal method and characterized using X-ray diffraction and scanning electron microscopy. MRI was carried out by use of a 1.5 Tesla clinical scanner. The T2 weighted images were prepared and the r2 relaxivity was calculated. The sizes of Fe3O4 nanoparticles and related nanocomposite were 13-24 nm and 80-150 nm, respectively. Results of MTT assay confirmed that the prepared nanocomposite is cytocompatible. The r2 relaxivity of the Fe3O4@ZSM-5 nanocomposite was 457.1 mM-1 s-1. This study suggests that the Fe3O4@ZSM-5 nanocomposite has potential to use as an MRI T2 contrast agent.

  3. Molecular imaging of atherosclerosis with nanoparticle-based fluorinated MRI contrast agents.

    Science.gov (United States)

    Palekar, Rohun U; Jallouk, Andrew P; Lanza, Gregory M; Pan, Hua; Wickline, Samuel A

    2015-01-01

    As atherosclerosis remains one of the most prevalent causes of patient mortality, the ability to diagnose early signs of plaque rupture and thrombosis represents a significant clinical need. With recent advances in nanotechnology, it is now possible to image specific molecular processes noninvasively with MRI, using various types of nanoparticles as contrast agents. In the context of cardiovascular disease, it is possible to specifically deliver contrast agents to an epitope of interest for detecting vascular inflammatory processes, which serve as predecessors to atherosclerotic plaque development. Herein, we review various applications of nanotechnology in detecting atherosclerosis using MRI, with an emphasis on perfluorocarbon nanoparticles and fluorine imaging, along with theranostic prospects of nanotechnology in cardiovascular disease.

  4. Silica-coated gold nanoplates as stable photoacoustic contrast agents for sentinel lymph node imaging

    Science.gov (United States)

    Luke, Geoffrey P.; Bashyam, Ashvin; Homan, Kimberly A.; Makhija, Suraj; Chen, Yun-Sheng; Emelianov, Stanislav Y.

    2013-11-01

    A biopsy of the first lymph node to which a tumor drains—the sentinel lymph node (SLN)—is commonly performed to identify micrometastases. Image guidance of the SLN biopsy procedure has the potential to improve its accuracy and decrease its morbidity. We have developed a new stable contrast agent for photoacoustic image-guided SLN biopsy: silica-coated gold nanoplates (Si-AuNPs). The Si-AuNPs exhibit high photothermal stability when exposed to pulsed and continuous wave laser irradiation. This makes them well suited for in vivo photoacoustic imaging. Furthermore, Si-AuNPs are shown to have low cytotoxicity. We tested the Si-AuNPs for SLN mapping in a mouse model where they exhibited a strong, sustained photoacoustic signal. Real-time ultrasound and photoacoustic imaging revealed that the Si-AuNPs quickly drain to the SLN, gradually spreading throughout a large portion of the node.

  5. alpha-Methylene and glycidic acid analogs of IPPA as potential myocardial imaging agents.

    Science.gov (United States)

    Ruyan, M K; Bakan, D A; Skinner, R W; Newman, C; Gross, M D; Counsell, R E

    1995-01-01

    Using organozinc cross-coupling reactions, two radiolabeled analogs of 15-(p-iodophenyl) pentadecanoic acid (IPPA) have been designed and synthesized as potential scintigraphic imaging agents for the heart. Both 15-(4-iodophenyl)-tridecylglycidic acid and 15-(4-iodophenyl)-2-methylene pentadecanoic acid were synthesized and radioiodinated. In tissue biodistribution studies in rats, only the alpha-methylene derivative of IPPA displayed a consistently higher heart to blood ratio and a substantially lower degree of thyroid accumulation than did IPPA alone. With respect to a scintigraphic imaging efficacy, the alpha-methylene analog of IPPA and IPPA itself showed essentially equivalent cardiac imaging profiles in rabbits, with a slight extension in imaging time for the alpha-methylene analog of IPPA.

  6. {alpha}-methylene and glycidic acid analogs of IPPA as potential myocardial imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Ruyan, M. K.; Bakan, D. A.; Skinner, R. W. S.; Newman, C.; Gross, M. D.; Counsell, R. E

    1995-01-01

    Using organozinc cross-coupling reactions, two radiolabeled analogs of 15-(p-iodophenyl) pentadecanoic acid (IPPA) have been designed and synthesized as potential scintigraphic imaging agents for the heart. Both 15-(4-iodophenyl)-tridecylglycidic acid and 15-(4-iodophenyl)-2-methylene pentadecanoic acid were synthesized and radioiodinated. In tissue biodistribution studies in rats, only the {alpha}-methylene derivative of IPPA displayed a consistently higher heart to blood ratio and a substantially lower degree of thyroid accumulation than did IPPA alone. With respect to a scintigraphic imaging efficacy, the {alpha}-methylene analog of IPPA and IPPA itself showed essentially equivalent cardiac imaging profiles in rabbits, with a slight extension in imaging time for the {alpha}-methylene analog of IPPA.

  7. Gold nanoparticle contrast agents in advanced X-ray imaging technologies.

    Science.gov (United States)

    Ahn, Sungsook; Jung, Sung Yong; Lee, Sang Joon

    2013-05-17

    Recently, there has been significant progress in the field of soft- and hard-X-ray imaging for a wide range of applications, both technically and scientifically, via developments in sources, optics and imaging methodologies. While one community is pursuing extensive applications of available X-ray tools, others are investigating improvements in techniques, including new optics, higher spatial resolutions and brighter compact sources. For increased image quality and more exquisite investigation on characteristic biological phenomena, contrast agents have been employed extensively in imaging technologies. Heavy metal nanoparticles are excellent absorbers of X-rays and can offer excellent improvements in medical diagnosis and X-ray imaging. In this context, the role of gold (Au) is important for advanced X-ray imaging applications. Au has a long-history in a wide range of medical applications and exhibits characteristic interactions with X-rays. Therefore, Au can offer a particular advantage as a tracer and a contrast enhancer in X-ray imaging technologies by sensing the variation in X-ray attenuation in a given sample volume. This review summarizes basic understanding on X-ray imaging from device set-up to technologies. Then this review covers recent studies in the development of X-ray imaging techniques utilizing gold nanoparticles (AuNPs) and their relevant applications, including two- and three-dimensional biological imaging, dynamical processes in a living system, single cell-based imaging and quantitative analysis of circulatory systems and so on. In addition to conventional medical applications, various novel research areas have been developed and are expected to be further developed through AuNP-based X-ray imaging technologies.

  8. Gold Nanoparticle Contrast Agents in Advanced X-ray Imaging Technologies

    Directory of Open Access Journals (Sweden)

    Sungsook Ahn

    2013-05-01

    Full Text Available Recently, there has been significant progress in the field of soft- and hard-X-ray imaging for a wide range of applications, both technically and scientifically, via developments in sources, optics and imaging methodologies. While one community is pursuing extensive applications of available X-ray tools, others are investigating improvements in techniques, including new optics, higher spatial resolutions and brighter compact sources. For increased image quality and more exquisite investigation on characteristic biological phenomena, contrast agents have been employed extensively in imaging technologies. Heavy metal nanoparticles are excellent absorbers of X-rays and can offer excellent improvements in medical diagnosis and X-ray imaging. In this context, the role of gold (Au is important for advanced X-ray imaging applications. Au has a long-history in a wide range of medical applications and exhibits characteristic interactions with X-rays. Therefore, Au can offer a particular advantage as a tracer and a contrast enhancer in X-ray imaging technologies by sensing the variation in X-ray attenuation in a given sample volume. This review summarizes basic understanding on X-ray imaging from device set-up to technologies. Then this review covers recent studies in the development of X-ray imaging techniques utilizing gold nanoparticles (AuNPs and their relevant applications, including two- and three-dimensional biological imaging, dynamical processes in a living system, single cell-based imaging and quantitative analysis of circulatory systems and so on. In addition to conventional medical applications, various novel research areas have been developed and are expected to be further developed through AuNP-based X-ray imaging technologies.

  9. MR imaging of brain pilocytic astrocytoma: beyond the stereotype of benign astrocytoma.

    Science.gov (United States)

    Gaudino, Simona; Martucci, Matia; Russo, Rosellina; Visconti, Emiliano; Gangemi, Emma; D'Argento, Francesco; Verdolotti, Tommaso; Lauriola, Libero; Colosimo, Cesare

    2017-01-01

    Pilocytic astrocytoma (PA) is the most common pediatric brain glioma and is considered the prototype of benign circumscribed astrocytoma. Despite its low malignancy, the CT and MRI features of brain PA may resemble those of much more aggressive brain tumors. Misdiagnosis of PA is particularly easy when it demonstrates MR morphological and non-morphological findings that are inconsistent with its non-aggressive nature and that overlap with the features of more aggressive brain tumors. Basing on the evidence that the variation in the histological, genetic, and metabolic "fingerprint" for brain PA is dependent on tumor location, and the hypothesis that tumor location is related to the broad spectrum of morphological and non-morphological MR imaging findings, the authors discuss the MR imaging appearance of brain PA using a location-based approach to underline the typical and less typical imaging features and the main differential diagnosis of brain PA. A brief summary of the main pathological and clinical features, the natural history, and the treatment of brain PA is also provided. A combination of morphological and non-morphological MR imaging features and a site-based approach to differential diagnosis are required for a pre-operative diagnosis. The new "cutting-edge" MR imaging sequences have the potential to impact the ease and confidence of pediatric brain tumor interpretation and offer a more efficient diagnostic work-up. Although the typical imaging features of brain pilocytic astrocytoma make radiological diagnosis relatively easy, an atypical and more aggressive appearance can lead to misdiagnosis. Knowing the broad spectrum of imaging characteristics on conventional and advanced MR imaging is important for accurate pre-operative radiological diagnosis and correctly interpreting changes during follow-up.

  10. Polypyrrole coated phase-change contrast agents for sono-photoacoustic imaging (Conference Presentation)

    Science.gov (United States)

    Li, David S.; Yoon, Soon Joon; Matula, Thomas J.; O'Donnell, Matthew; Pozzo, Lilo D.

    2017-03-01

    A new light and sound sensitive nanoemulsion contrast agent is presented. The agents feature a low boiling point liquid perfluorocarbon core and a broad light spectrum absorbing polypyrrole (PPy) polymer shell. The PPy coated nanoemulsions can reversibly convert from liquid to gas phase upon cavitation of the liquid perfluorocarbon core. Cavitation can be initiated using a sufficiently high intensity acoustic pulse or from heat generation due to light absorption from a laser pulse. The emulsions can be made between 150 and 350 nm in diameter and PPy has a broad optical absorption covering both the visible spectrum and extending into the near-infrared spectrum (peak absorption 1053 nm). The size, structure, and optical absorption properties of the PPy coated nanoemulsions were characterized and compared to PPy nanoparticles (no liquid core) using dynamic light scattering, ultraviolet-visible spectrophotometry, transmission electron microscopy, and small angle X-ray scattering. The cavitation threshold and signal intensity were measured as a function of both acoustic pressure and laser fluence. Overlapping simultaneous transmission of an acoustic and laser pulse can significantly reduce the activation energy of the contrast agents to levels lower than optical or acoustic activation alone. We also demonstrate that simultaneous light and sound cavitation of the agents can be used in a new sono-photoacoustic imaging method, which enables greater sensitivity than traditional photoacoustic imaging.

  11. Research on image fusion of missile team based on multi-agent cooperative blackboard model

    Science.gov (United States)

    Sen, Guo; Munan, Li

    The target of cooperative engagement of missile teams is to furthest improve hit rate of target according to communication and cooperation among missiles. In this paper the problems of image fusion between missile teams in complex combat environment was analyzed, after which an muti-agent blackboard cooperative model was presented and a public information platform of missile team is built according to this model. Through these, the fusion of images taken from muti-sensor of missiles can be realized and the hit rate of attacking target will be improved. At last, an simulation experiment were performed, and the feasibility of the method is proved by simulation experiment.

  12. Gd-Si Oxide Nanoparticles as Contrast Agents in Magnetic Resonance Imaging.

    Science.gov (United States)

    Cabrera-García, Alejandro; Vidal-Moya, Alejandro; Bernabeu, Ángela; Pacheco-Torres, Jesús; Checa-Chavarria, Elisa; Fernández, Eduardo; Botella, Pablo

    2016-06-08

    We describe the synthesis, characterization and application as contrast agents in magnetic resonance imaging of a novel type of magnetic nanoparticle based on Gd-Si oxide, which presents high Gd3+ atom density. For this purpose, we have used a Prussian Blue analogue as the sacrificial template by reacting with soluble silicate, obtaining particles with nanorod morphology and of small size (75 nm). These nanoparticles present good biocompatibility and higher longitudinal and transversal relaxivity values than commercial Gd3+ solutions, which significantly improves the sensitivity of in vivo magnetic resonance images.

  13. Gaucher disease in the liver on hepatocyte specific contrast agent enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ayyala, Rama S. [Morgan Stanley Children' s Hospital, Department of Radiology, Columbia University Medical Center, New York, NY (United States); Teot, Lisa A. [Boston Children' s Hospital, Department of Pathology, Harvard Medical School, Boston, MA (United States); Perez Rossello, Jeanette M. [Boston Children' s Hospital, Department of Radiology, Harvard Medical School, Boston, MA (United States)

    2017-04-15

    Gaucher disease is a hereditary lipid storage disorder that affects the enzyme beta glucocerebrosidase, causing accumulation of glucocerebroside in macrophages of the reticuloendothelial system. Accumulation can occur in the liver and spleen, manifesting as hepatosplenomegaly, as well as within the bone marrow. Hepatic involvement is usually diffuse but can occasionally manifest as focal liver lesions. We present a case of a 2-year-old boy with Gaucher disease and an infiltrating liver lesion detected on imaging, which was pathologically shown to be focal changes related to the disease. Imaging characteristics of this lesion using hepatocyte specific contrast agent enhanced MRI, which have not been previously discussed in the literature, are described. (orig.)

  14. Metal complex-based templates and nanostructures for magnetic resonance/optical multimodal imaging agents

    OpenAIRE

    Galindo Millan, Jealemy

    2012-01-01

    In this thesis, new approaches directed towards simple and functional imaging agents (IAs) for magnetic resonance (MR) and fluorescence multimodal imaging are proposed. In Chapter 3, hybrid silver nanostructures (hAgNSs), grown using a polyamino carboxylic acid scaffold, namely 1,4,7,10-tetraaza-1-(1- aminobutyl)-4,7,10-triacetic acid cyclododecane (AB-DO3A), are described. The engineered hAgNSs consist of a “large” silver nanoparticle (AgNP, stabilized by the AB-DO3A scaffold), which can act...

  15. Upconversion nanoparticle as a theranostic agent for tumor imaging and therapy

    Directory of Open Access Journals (Sweden)

    Wenkai Fang

    2016-07-01

    Full Text Available Upconversion nanoparticles (UCNPs as a promising material are widely studied due to their unique optical properties. The material can be excited by long wavelength light and emit visible wavelength light through multiphoton absorption. This property makes the particles highly attractive candidates for bioimaging and therapy application. This review aims at summarizing the synthesis and modification of UCNPs, especially the applications of UCNPs as a theranostic agent for tumor imaging and therapy. The biocompatibility and toxicity of UCNPs are also further discussed. Finally, we discuss the challenges and opportunities in the development of UCNP-based nanoplatforms for tumor imaging and therapy.

  16. Adrenomyeloneuropathy, a dynamic progressive disorder: brain magnetic resonance imaging of two cases

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Yuan-Heng; Chen, Ya-Fang; Liu, Hon-Man [Department of Medical Imaging, National Taiwan University Hospital, 7 Chung-Shan South Road, 100, Taipei (Taiwan)

    2004-04-01

    Adrenomyeloneuropathy (AMN) is a phenotype variant of X-linked adrenoleukodystrophy. We present two patients with adult-onset AMN who were initially suspected to have demyelinating disorders radiologically and finally diagnosed on the basis of laboratory data. The brain magnetic resonance images showed abnormal signal intensity at pyramidal tracts and cerebellar hemisphere bilaterally with abnormal enhancement after contrast medium administration. Review of the literature shows that the brain magnetic resonance findings of adrenomyeloneuropathy may include normal brain, tract demyelination, white matter demyelination, or brain atrophy. Disease progression was demonstrated by follow-up imaging. (orig.)

  17. Incorporating virtual reality graphics with brain imaging for assessment of sport-related concussions.

    Science.gov (United States)

    Slobounov, Semyon; Sebastianelli, Wayne; Newell, Karl M

    2011-01-01

    There is a growing concern that traditional neuropsychological (NP) testing tools are not sensitive to detecting residual brain dysfunctions in subjects suffering from mild traumatic brain injuries (MTBI). Moreover, most MTBI patients are asymptomatic based on anatomical brain imaging (CT, MRI), neurological examinations and patients' subjective reports within 10 days post-injury. Our ongoing research has documented that residual balance and visual-kinesthetic dysfunctions along with its underlying alterations of neural substrates may be detected in "asymptomatic subjects" by means of Virtual Reality (VR) graphics incorporated with brain imaging (EEG) techniques.

  18. Breast Cancer Imaging Using the Near-Infrared Fluorescent Agent, CLR1502

    Directory of Open Access Journals (Sweden)

    Melissa L. Korb

    2015-01-01

    Full Text Available Positive margins after breast conservation surgery represent a significant problem in the treatment of breast cancer. The near-infrared fluorescence agent CLR1502 (Cellectar Biosciences, Madison, WI was studied in a preclinical breast cancer model to determine imaging properties and ability to detect small islands of malignancy. Nude mice bearing human breast cancer flank xenografts were given a systemic injection of CLR1502, and imaging was performed using LUNA (Novadaq Technologies Inc., Richmond, BC and Pearl Impulse (LI-COR Biosciences, Lincoln, NE devices. Normal tissues were examined for fluorescence signal, and conventional and fluorescence histology was performed using the Odyssey scanner. Peak tumor to background ratio occurred 2 days after injection with CLR1502. The smallest amount of tumor that was imaged and detected using these devices was 1.9 mg, equivalent to 1.9 × 106 cells. The highest fluorescence signal was seen in tumor and normal lymph node tissue, and the lowest fluorescence signal was seen in muscle and plasma. Human breast cancer tumors can be imaged in vivo with multiple optical imaging platforms using CLR1502. This pilot study supports further investigations of this fluorescent agent for improving surgical resection of malignancies, with the goal of eventual clinical translation.

  19. Breast Cancer Imaging Using the Near-Infrared Fluorescent Agent, CLR1502.

    Science.gov (United States)

    Korb, Melissa L; Warram, Jason M; Grudzinski, Joseph; Weichert, Jamey; Jeffery, Justin; Rosenthal, Eben L

    2015-01-01

    Positive margins after breast conservation surgery represent a significant problem in the treatment of breast cancer. The near-infrared fluorescence agent CLR1502 (Cellectar Biosciences, Madison, WI) was studied in a preclinical breast cancer model to determine imaging properties and ability to detect small islands of malignancy. Nude mice bearing human breast cancer flank xenografts were given a systemic injection of CLR1502, and imaging was performed using LUNA (Novadaq Technologies Inc., Richmond, BC) and Pearl Impulse (LI-COR Biosciences, Lincoln, NE) devices. Normal tissues were examined for fluorescence signal, and conventional and fluorescence histology was performed using the Odyssey scanner. Peak tumor to background ratio occurred 2 days after injection with CLR1502. The smallest amount of tumor that was imaged and detected using these devices was 1.9 mg, equivalent to 1.9 × 106 cells. The highest fluorescence signal was seen in tumor and normal lymph node tissue, and the lowest fluorescence signal was seen in muscle and plasma. Human breast cancer tumors can be imaged in vivo with multiple optical imaging platforms using CLR1502. This pilot study supports further investigations of this fluorescent agent for improving surgical resection of malignancies, with the goal of eventual clinical translation.

  20. Transforming a Targeted Porphyrin Theranostic Agent into a PET Imaging Probe for Cancer.

    Science.gov (United States)

    Shi, Jiyun; Liu, Tracy W B; Chen, Juan; Green, David; Jaffray, David; Wilson, Brian C; Wang, Fan; Zheng, Gang

    2011-01-01

    Porphyrin based photosensitizers are useful agents for photodynamic therapy (PDT) and fluorescence imaging of cancer. Porphyrins are also excellent metal chelators forming highly stable metallo-complexes making them efficient delivery vehicles for radioisotopes. Here we investigated the possibility of incorporating (64)Cu into a porphyrin-peptide-folate (PPF) probe developed previously as folate receptor (FR) targeted fluorescent/PDT agent, and evaluated the potential of turning the resulting (64)Cu-PPF into a positron emission tomography (PET) probe for cancer imaging. Noninvasive PET imaging followed by radioassay evaluated the tumor accumulation, pharmacokinetics and biodistribution of (64)Cu-PPF. (64)Cu-PPF uptake in FR-positive tumors was visible on small-animal PET images with high tumor-to-muscle ratio (8.88 ± 3.60) observed after 24 h. Competitive blocking studies confirmed the FR-mediated tracer uptake by the tumor. The ease of efficient (64)Cu-radiolabeling of PPF while retaining its favorable biodistribution, pharmacokinetics and selective tumor uptake, provides a robust strategy to transform tumor-targeted porphyrin-based photosensitizers into PET imaging probes.

  1. Neuropathic pain in ankylosing spondylitis: a psychophysics and brain imaging study.

    Science.gov (United States)

    Wu, Qi; Inman, Robert D; Davis, Karen D

    2013-06-01

    To determine whether there is a neuropathic component in ankylosing spondylitis (AS) back pain and to delineate gray matter brain abnormalities associated with AS. Seventeen patients with back pain secondary to AS who were not receiving biologic agents and 17 age- and sex-matched healthy controls consented to participate in the study and were assessed using the painDETECT instrument (scores of ≤12 indicating low probability of neuropathic pain) and the McGill Pain Questionnaire. Mechanical and thermal thresholds were determined in all subjects, and brain gray matter was assessed by 3T magnetic resonance imaging. Eleven of the 17 AS patients had painDETECT scores of >12. The patients had decreased mechanical and cold sensitivity on the dorsum of their feet but did not have altered pain thresholds. Compared to controls, the AS patients exhibited cortical thinning in the primary somatosensory, insular, anterior cingulate, and anterior mid-cingulate cortices and the supplemental motor area, and increased gray matter volume in the thalamus and putamen. Scores on the painDETECT in AS patients were correlated with decreased gray matter in the primary somatosensory cortex and with increased gray matter in the motor cortex, anterior cingulate cortex, prefrontal cortex, thalamus, and striatum. The present findings indicate that neuropathic pain occurs in AS. Furthermore, abnormal brain gray matter and neural correlates of neuropathic pain are concordant with the clinical picture of AS, which includes sensorimotor and mood deficits as well as neuropathic pain symptoms. These results suggest that back pain in AS is a mixed pain condition that includes a neuropathic pain component. Copyright © 2013 by the American College of Rheumatology.

  2. Quantitative functional lung imaging with synchrotron radiation using inhaled xenon as contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, S. [TIMC-PRETA, UMR CNRS 5525, Laboratoire de Physiologie, Universite Joseph Fourier, Faculte de Medecine, Domaine de la Merci, Grenoble (France)]. E-mail: sam.bayat@imag.fr; Le Duc, G.; Berruyer, G.; Nemoz, C.; Monfraix, S.; Fiedler, S.; Thomlinson, W. [European Synchrotron Radiation Facility, BP 220, Grenoble (France); Porra, L.; Suortti, P. [Department of Physics, University of Helsinki, Helsinki (Finland); Standertskjoeld-Nordenstam, C.G. [Department of Radiology, University of Helsinki Central Hospital, Helsinki (Finland); Sovijaervi, A.R.A. [Department of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, Helsinki (Finland)

    2001-12-01

    Small airways play a key role in the distribution of ventilation and in the matching of ventilation to perfusion. The purpose of this study was to introduce an imaging method that allows measurement of regional lung ventilation and evaluation of the function of airways with a small diameter. The experiments were performed at the Medical Beamline of the European Synchrotron Radiation Facility. Monochromatic synchrotron radiation beams were used to obtain quantitative respiration-gated images of lungs and airways in two anaesthetized and mechanically ventilated rabbits using inhaled stable xenon (Xe) gas as a contrast agent. Two simultaneous images were acquired at two different energies, above and below the K-edge of Xe. Logarithmic subtraction of the two images yields absolute Xe concentrations. This technique is known as K-edge subtraction (KES) radiography. Two-dimensional planar and CT images were obtained showing spatial distribution of Xe concentrations within the airspaces, as well as the dynamics of filling with Xe. Bronchi down to 1 mm in diameter were visible both in the subtraction radiographs and in tomographic images. Absolute concentrations of Xe gas were calculated within the tube carrying the inhaled gas mixture, small and large bronchi, and lung tissue. Local time constants of ventilation with Xe were obtained by following the evolution of gas concentration in sequential computed tomography images. The results of this first animal study indicate that KES imaging of lungs with Xe gas as a contrast agent has great potential in studies of the distribution of ventilation within the lungs and of airway function, including airways with a small diameter. (author)

  3. Segmentation and representation of lesions in MRI brain images

    Science.gov (United States)

    Tao, Yi; Grosky, William I.; Zamorano, Lucia J.; Jiang, Zhaowei; Gong, JianXing

    1999-05-01

    In this paper, we address the NSPS (a Neurological Surgery Planning System developed at the Neurological Surgery Department of Wayne State University) approaches for segmenting and representing lesions in MRI brain images. Initially, the 2D segmentation algorithm requires the input of a seed (an individual pixel or a small region) and a threshold to control the formation of a lesion region. The 3D segmentation algorithm requires the input of a seed, along with the threshold computed automatically from the corresponding three sample thresholds of lesion regions in sagittal, coronal, and axial views, to form a lesion volume. Then, a novel method is developed to represent the segmented lesion regions with feature point histograms, obtained by discretizing and counting the angles produced from the resulting Delaunay triangulation of a set of feature points which characterize the shape of the lesion region. The proposed shape representation technique is translation, scale, and rotation independent. Through various experiment results, we demonstrate the efficacy of the NSPS methodologies. Finally, based on the lesion representation scheme, we present a prototype system architecture for neurological surgery training. The implemented system will work in a Web-based environment, allowing neurosurgeons to query and browse various patients-related medical records in an effective and efficient way.

  4. Speech system of the brain: Insight via functional imaging methods

    Directory of Open Access Journals (Sweden)

    Kristjan Sancin

    2004-08-01

    Full Text Available The study of neural correlates of language has always lagged behind the study of other aspects of behavior and cognition due to the lack of an animal model. Clinical data led to the idea that language perception is localized in the posterior superior temporal lobe (Wernicke's area and functions related to speech production are localized in the lateral frontal lobe (Broca's area of the dominant hemisphere. Recent data from electrophysiological and functional neuroimaging investigations shows that the roles of Wernicke's and Broca's areas are not as clear as they appeared. A variety of cortical and subcortical regions have been found to be critically important for language processing. Functional magnetic resonance imaging (fMRI can be used to study language system of the brain. When planning certain neurosurgical interventions, it is important to determine hemispheric language dominance and localization of language functions in order to avoid damaging these areas. Some fMRI language paradigms promise a completely noninvasive way of localizing language functions in an individual patient – a possible substitute for the tests currently in use. In our lab, we have recently started to use fMRI for localization of cortical language areas in healthy individuals and in neurological patients.

  5. Imaging brain injury using time-resolved near infrared light scanning.

    Science.gov (United States)

    Van Houten, J P; Benaron, D A; Spilman, S; Stevenson, D K

    1996-03-01

    Conventional brain imaging modalities are limited in that they image only secondary physical manifestations of brain injury, which may occur well after the actual insult to the brain and represent irreversible structural changes. A real-time continuous bedside monitor that images functional changes in cerebral blood flow or oxygenation might allow for recognition of brain tissue ischemia or hypoxia before the development of irreversible injury. Visible and near infrared light pass through human bone and tissue in small amounts, and the emerging light can be used to form images of the interior structure of the tissue and measure tissue blood flow and oxygen utilization based on light absorbance and scattering. We developed a portable time-of-flight and absorbance system which emits pulses of near infrared light into tissue and measures the transit time of photons through the tissue. Images can then be reconstructed mathematically using either absorbance or scattering information. Pathologic brain specimens from adult sheep and human newborns were studied with this device using rotational optical tomography. Images generated from these optical scans show that neonatal brain injuries such as subependymal and intraventricular hemorrhages can be successfully identified and localized. Resolution of this system appears to be better than 1 cm at a tissue depth of 5 cm, which should be sufficient for imaging some brain lesions as well as for detection of regional changes in cerebral blood flow and oxygenation. We conclude that light-based imaging of cerebral structure and function is feasible and may permit identification of patients with impending brain injury as well as monitoring of the efficacy of intervention. Construction of real-time images of brain structure and function is now underway using a fiber optic headband and nonmechanical rotational scanner allowing comfortable, unintrusive monitoring over extended periods of time.

  6. MRI contrast agent for molecular imaging of the HER2/neu receptor using targeted magnetic nanoparticles

    Science.gov (United States)

    Rasaneh, Samira; Rajabi, Hossein; Babaei, Mohammad Hossein; Akhlaghpoor, Shahram

    2011-06-01

    In this study, Trastuzumab modified Magnetic Nanoparticles (TMNs) were prepared as a new contrast agent for detecting HER2 (Human epidermal growth factor receptor-2) expression tumors by magnetic resonance imaging (MRI). TMNs were prepared based on iron oxide nanoparticles core and Trastuzumab modified dextran coating. The TMNs core and hydrodynamic size were determined by transmission electron microscopy and dynamic light scattering. TMNs stability and cytotoxicity were investigated. The ability of TMNs for HER2 detection were evaluated in breast carcinoma cell lines (SKBr3 and MCF7 cells) and tumor-bearing mice by MRI and iron uptake determination. The particles core and hydrodynamic size were 9 ± 2.5 and 41 ± 15 nm (size range: 15-87 nm), respectively. The molar antibody/nanoparticle ratio was 3.1-3.5. TMNs were non-toxic to the cells below the 30 μg (Fe)/mL concentration and good stable up to 8 weeks in PBS buffer. TMNs could detect HER2 oncogenes in the cells surface with imagable contrast by MRI. The invivo study in mice bearing tumors indicated that TMNs possessed a good diagnostic ability as HER2 specific contrast agent by MRI. TMNs were demonstrated to be able to selectively accumulate in the tumor cells, with a proper signal enhancement in MRI T2 images. So, the complex may be considered for further investigations as an MRI contrast agent for detection of HER2 expression tumors in human.

  7. Manganese ferrite nanoparticle micellar nanocomposites as MRI contrast agent for liver imaging.

    Science.gov (United States)

    Lu, Jian; Ma, Shuli; Sun, Jiayu; Xia, Chunchao; Liu, Chen; Wang, Zhiyong; Zhao, Xuna; Gao, Fabao; Gong, Q